Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

TechLibrary
Table of Contents
Navigation  Back up to About Overview 
ContentIndex
 
[+] Expand All
[-] Collapse All

New Features in Junos OS Release 12.2 for ACX Series Routers

Powered by Junos OS, ACX Series Universal Access Routers provide superior management for rapid provisioning to the access network. They are designed to support residential, mobile, and business access. ACX Series routers include the ACX1000, ACX1100, ACX2000, and the ACX2100 routers.

The following are key features of ACX Series routers:

  • High performance up to 10 Gigabit Ethernet capable
  • Seamless MPLS traffic engineering for optimal paths and per-customer quality of service in the access layer
  • Built-in Precision Timing Protocol (PTP) and Synchronized Ethernet to eliminate dropped calls and data retransmissions
  • Environmentally hardened with 65 W Power over Ethernet Plus (PoE+)

The following features have been added to Junos OS Release 12.2 for ACX Series Universal Access Routers. Following the description is the title of the manual or manuals to consult for further information:

Hardware

  • New ACX1000 Universal Access Router—Starting in Release 12.2, Junos OS supports the ACX1000 router. This router enables a wide range of business and residential applications and services, including microwave cell site aggregation, MSO mobile backhaul service cell site deployment, and service provider or operator cell site deployment. The ACX1000 router is a compact access router that is one rack unit (U) tall. The ACX1000 router contains 8 T1 and E1 ports and 8 Gigabit Ethernet ports. The ACX1000 router also supports either 4 RJ45 (Cu) ports or installation of 4 Gigabit Ethernet SFP transceivers.

    [See ACX1000 Universal Access Router.]

  • New ACX2000 Universal Access Router—Starting in Release 12.2, Junos OS supports the ACX2000 router. This router enables a wide range of business and residential applications and services, including microwave cell site aggregation, MSO mobile backhaul service cell site deployment, and service provider or operator cell site deployment. The ACX2000 router is a compact access router that is one rack unit (U) tall. The ACX2000 router contains 16 T1 and E1 ports, 6 Gigabit Ethernet ports, and 2 PoE ports. The ACX2000 router also supports installation of two Gigabit Ethernet SFP transceivers and two 10-Gigabit Ethernet SFP+ transceivers.

    [See ACX2000 Universal Access Router.]

Class of Service (CoS)

  • Existing CoS features supported on the ACX Series Universal Access Routers—Existing Junos OS class-of-service (CoS) features are supported without changes to statements or functionality.

    The following key CoS features are supported:

    • Physical interface-based classifiers at the [edit class-of-service interfaces interfaces-name] hierarchy level.
    • Fixed classification for all ingress packets traversing a logical interface to a single forwarding class. Fixed classification is supported on all interfaces types.
    • Experimental (EXP) bits located in each MPLS label and used to encode the CoS value of a packet as it traverses an LSP. To configure global EXP bits, include the exp statement at the [edit class-of-service system-defaults classifiers] hierarchy level.
    • Attachment of the following rewrite rules to the physical interface at the [edit class-of-service interfaces interface-name rewrite-rules] hierarchy level: IP ToS, DSCP, and IEEE 802.1p bit value.
    • Rewrite rules for MPLS EXP bits on the logical interface at the [edit class-of-service interfaces interface-name unit unit-number rewrite-rule] hierarchy level.

      Note: Fine-grained rewrite is not possible, even when you use multifield filters.

    Queuing and scheduling features include:

    • Support for up to eight forwarding classes.
    • Up to eight egress queues per port.
    • Internal buffer of 2 MB with per-egress queue buffer management.
    • Three weighted random early detection (WRED) curves for TCP and one WRED curve for non-TCP. There are two fill levels and two drop probabilities per WRED curve; the drop probability corresponding to the first fill must be zero.
    • Strict-priority and weighted deficit round-robin scheduling.
    • Multiple strict-priority queues per port.
    • Per-queue committed information rate (CIR) and peak information rate (PIR).
    • Per-physical-port shaping.

    Queue statistics features include:

    • Per-egress-queue enqueue statistics in packets, bytes, packets per second (pps), and bits per second (bps).
    • Per-egress-queue transmit statistics in packets, bytes, pps, and bps.
    • Per-egress-queue drop statistics in packets and pps.

Infrastructure

  • Dual-root partitioning—All ACX Series routers support dual-root partitioning. Dual-root partitioning means that the primary and backup Junos OS images are kept in two independently bootable root partitions. If the primary root partition becomes corrupted, the system remains fully functional by booting from the backup Junos OS image located in the other root partition.

    [See Dual-Root Partitioning ACX Series Universal Access Routers Overview.]

Interfaces and Chassis

  • Junos OS support for chassis management of ACX Series Universal Access Routers— Junos OS Release 12.2 supports the following ACX Series routers:
    • ACX1000 Universal Access Router
    • ACX2000 Universal Access Router

    The ACX Series router chassis does not have redundancy support.

    The following CLI operational mode commands support chassis management operations on an ACX Series router:

    Show commands:

    • show chassis alarms
    • show chassis craft-interface
    • show chassis environment
    • show chassis feb
    • show chassis firmware
    • show chassis fpc < pic-status >
    • show chassis hardware < clei-models | detail | extensive | models >
    • show chassis mac-addresses
    • show chassis routing-engine
    • show chassis pic fpc-slot fpc-slot pic-slot pic slot

    Request command:

    • request chassis feb restart slot slot-number

    Restart command:

    • restart chassis-control < gracefully | immediately | soft >

    [See System Basics: Chassis-Level Features Configuration Guide.]

  • Gigabit Ethernet physical interface features (ACX Series Universal Access Routers)—The following Gigabit Ethernet physical interface features are supported on ACX Series Universal Access routers:
    • Autonegotiation for Gigabit Ethernet interfaces—Exchange of the following parameters is supported: speed and duplex mode. Autonegotiation can be enabled or disabled. When autonegotiation is disabled, the speed has to be explicitly configured to 10–100 Mbps. To configure autonegotiation, include the auto-negotiation statement at the [edit interfaces interface-name gigether-options] hierarchy level. To disable the autonegotiation, include the no-auto-negotiation statement at the [edit interfaces interface-name gigether-options] hierarchy level.

      [See Gigabit Ethernet Autonegotiation Overview and Junos OS Ethernet Interfaces Configuration Guide .]

    • Event handling of SFP insertion and removal—When you insert a small form-factor pluggable transceiver (SFP), the port needs to be configured with the correct speed for that interface (Gigabit Ethernet or 10-Gigabit Ethernet). The following details apply to SFP insertion and removal:
      • SFP-based 1-Gigabit Ethernet interfaces support the following standards:
        • 1000BASE-SX
        • 1000BASE-LX
        • 1000BASE-T
        • 100BASE-FX (100M)
      • The 10-Gigabit Ethernet interfaces based on SFP+ support the following standards in addition to the 1-Gigabit Ethernet interface standards mentioned above:
        • 10GBASE-SR
        • 10GBASE-LR
      • On an SFP+ port, the port speed is not set by autonegotiation. Instead, it is determined by the speed of the SFP that is inserted or removed. The default speed of the SFP+ port is 10 Gbps. However, when a Gigabit Ethernet SFP is inserted in the SFP+ slot, Junos OS changes the speed to 1 Gbps. When the Gigabit Ethernet SFP is removed, the port speed is automatically reset to the default 10 Gbps.

        [See Junos OS Interfaces Fundamentals Configuration Guide .]

    • Explicit disabling of the physical interface—Disable a physical interface by effectively unconfiguring it. To disable an interface, include the disable statement at the [edit interfaces interface-name] hierarchy level.

      [See disable (Interface).]

    • Loopback—Local loopback is supported at the gigether-options hierarchy level. Local loopback allows packets to flow in toward the system. To configure the local loopback, include the loopback statement at the [edit interfaces interface-name gigether-options] hierarchy level.

      [See loopback (Aggregated Ethernet, Fast Ethernet, and Gigabit Ethernet).]

    • Loss of signal (LOS) alarm—A LOS alarm indicates that a signal could not be detected at the physical interface level. The LOS alarm is generated by the physical interface and displays a Link Up or Link Down event. To display LOS and other alarms, issue the show interfaces interface-name extensive command.

      [See show interfaces extensive.]

    • Maximum transmission unit (MTU)—Specify the MTU size for the interface. To configure the MTU, specify the bytes in the mtu statement at the [edit interfaces interface-name] hierarchy level.

      [See Configuring the Media MTU.]

    • Remote fault notification for 10-Gigabit Ethernet interfaces—Notifies each end of a connection of the failure at that end. When the failure is identified, the link is brought down and the LED light is turned off. This feature is not user configured.

      [See Detecting Remote Faults.]

    • Statistics collection and handling—Port-level input and output error statistics and the logical interface level statistics are collected automatically from the Packet Forwarding Engine. To display statistics, issue the show interfaces interface-name (brief | extensive) operational mode command.

      [See show interfaces statistics.]

    Note: The ACX Series routers do not support flow control based on PAUSE frames.

    [See Junos OS Ethernet Interfaces Configuration Guide  and Junos OS System Basics Configuration Guide .]

  • Media type selection (ACX1000 Universal Access routers)—You can select the media type (copper or fiber) for the 1-Gigabit Ethernet interfaces. To specify the media type, include the new media-type statement with the copper or fiber option at the [edit interfaces interface-name] hierarchy level.

    Note: Media type selection is applicable to ports only in slot 2.

    [See Junos OS Ethernet Interfaces Configuration Guide .]

  • IEEE 802.1ag OAM CFM and ITU-T Y.1731—The ACX Series routers support the IEEE 802.1ag standard for Operation, Administration, and Management (OAM) connectivity fault management (CFM) and the ITU-T Y.1731 standard for Ethernet service OAM.

    The IEEE 802.1ag standard defines mechanisms for end-to-end Ethernet service assurance over any path, whether a single link or multiple links spanning networks composed of multiple LANs.

    The ITU-T Y.1731 uses different terminology than IEEE 802.1ag and in addition defines Ethernet service OAM features for fault monitoring, diagnostics, and performance monitoring.

    The following key CFM and Ethernet service OAM features are supported:

    • Continuity check
    • Loopback messages
    • Traceroute messages
    • Linktrace messages

    In addition, the following key ITU-T Y.1731 Ethernet Service OAM features are supported:

    • Performance monitoring
      • Delay measurements
      • Loss measurements

    Note: Maintenance association intermediate points (MIPs) are not supported on the ACX Series routers.

    Note: The test signal, automatic protection switching, maintenance communication channel, experimental, and vendor-specific PDUs are not supported for generation or receipt in Junos OS or on the ACX Series routers.

    The proactive and dual-ended loss measurement functionality of ITU-T Y1731 is not supported.

    [See IEEE 802.1ag OAM Connectivity Fault Management Overview, ITU-T Y.1731 Ethernet Service OAM, and Ethernet Interfaces.]

  • IEEE 802.3ah OAM link-fault management—The ACX Series routers support the IEEE 802.3ah standard for Operation, Administration, and Maintenance (OAM). The IEEE 802.3ah standard defines a set of link fault management mechanisms to detect and report link faults on a single point-to-point Ethernet LAN. The following OAM link fault management features are supported:
    • Discovery
    • Link monitoring
    • Remote fault detection
    • Remote loopback

    [See IEEE 802.3ah OAM Link-Fault Management Overview.]

  • Junos OS support for ACX Series Universal Access Routers—Starting with Release 12.2R2, Junos OS supports the following ACX Series routers:
    • ACX1100 Universal Access Routers
    • ACX2100 Universal Access Routers

    The following show chassis commands are supported on the ACX1100 and the ACX2100 routers:

    • show chassis fpc
    • show chassis fpc fpc-slot
      • On ACX1100 routers, replace fpc-slot with value 0.
      • On ACX2100 routers, replace fpc-slot with a value 0 through 1.
    • show chassis fpc detail
    • show chassis fpc pic-status

    [See show chassis fpc.]

  • T1 and E1 interfaces time-division multiplexing (TDM) support—Existing Junos OS TDM features are supported without changes to statements or functionality. The following key TDM features for Channelized T1 (ct1) interfaces and Channelized E1 (ce1) interfaces are supported:
    • T1/E1 ports—The ACX1000 router has 8 built-in TDM ports. The ACX2000 router has 16 built-in TDM ports. T1/E1 mode selection is at the PIC level. To set the T1/E1 mode, include the framing statement with the t1 or e1 option at the [chassis fpc 0 pic slot-number] hierarchy level. All ports can be T1 or E1. Mixing T1s and E1s is not supported.

      [See framing.]

    • T1/E1 channelization—Full channelization is supported. Partitioning is not supported. To configure full channelization, include the no-partition statement at the [edit interfaces ct1-fpc/pic/port] hierarchy level or at the [edit interfaces ce1-fpc/pic/port] hierarchy level, depending on the interface type.

      [See no-partition.]

    • T1/E1 encapsulation—Structure-Agnostic TDM over Packet (SAToP) defined in RFC 4553 is supported. SAToP is used to transport complete TDM frames across the transport network, creating a smooth migration from legacy TDM to the central office. Traffic is kept at a constant bit rate of 1.544 Mbps for T1 and 2.048 Mbps plus overhead for E1 interfaces.

      [See SAToP Emulation on T1 and E1 Interfaces Overview.]

    • Alarms, defects, and statistics—Display alarms, defects, and statistics for interfaces running on the ACX Series routers.

      [See show interfaces (T1 or E1).]

    • BERT algorithms—Run BERT for interfaces running on the ACX Series routers.

      [See Configuring T1 BERT Properties and test interface t1-bert-start.]

    • External and internal loopback—Use loopback testing to isolate interface problems. By default, loopback is not configured.

      [See Configuring T1 Loopback Capability, Configuring E1 Loopback Capability, Junos OS Interfaces Network Operations Guide , and Junos OS E1/E3/T1/T3 Interfaces Configuration Guide .]

  • ATM time-division multiplexing (TDM) support—Existing Junos OS TDM features are supported without changes to statements or functionality. The following key TDM features for ATM are supported:
    • Inverse multiplexing for ATM (IMA)—Defined by the ATM Forum IMA specification version 1.1. IMA is a standardized technology used to transport ATM traffic over a bundle of T1 and E1 interfaces, also known as an IMA group. Up to 8 links per bundle and 16 bundles per PIC are supported.

      [See Configuring Inverse Multiplexing for ATM (IMA).]

    • Inverse multiplexing for ATM (IMA) Layer 2 encapsulation—Layer 2 encapsulation for IMA pseudowire initiation and termination on the ACX Series routers is supported. To configure encapsulation at the logical interface level, include the encapsulation statement with the atm-ccc-cell-relay or atm-ccc-vc-mux option at the [edit interface interface-name unit logical-unit-number] hierarchy level.

      [See Understanding Encapsulation on an Interface (ACX Series Routers).]

  • Denied packets counter—The show interfaces command for ATM interfaces, show interfaces at-fpc/pic/port extensive, supports a new field: denied packets. The denied packets field displays the number of packets dropped because of VLAN priority deny packets or because of an error in the forwarding configuration that might cause a negative frame length, that is, the stripping size is larger than the packet size.

    [See show interfaces (ATM).]

  • TDM and ATM class-of-service (CoS)—Junos OS CoS enables you to classify traffic into classes and offer various levels of throughput and packet loss when congestion occurs. Fixed classification is supported on the ACX Series routers. To configure fixed classification, include the forwarding-class statement at the [edit class-of-service interfaces interface-name unit logical-unit-number] hierarchy level.

    [See forwarding-class (Interfaces) and CoS on ACX Series Universal Access Routers Features Overview.]

  • ATM policing and shaping–Policing, or rate limiting, is an important component of firewall filters that you can use to limit the amount of traffic that passes into or out of an interface. Shaping uses queuing and scheduling to shape the outgoing traffic. For more information about supported policing and shaping on the ACX Series routers, see the Firewalls section of these release notes.

    [See Standard Firewall Filter Match Conditions and Actions on ACX Series Routers Overview.]

  • TDM CESoPSN (ACX1000 and ACX2000 routers)—Structure-aware TDM Circuit Emulation Service over Packet Switched Network (CESoPSN) is a method of encapsulating TDM signals into CESoPSN packets, and in the reverse direction, decapsulating CESoPSN packets back into TDM signals—also, referred to as Interworking Function (IWF). The following CESoPSN features are supported:
    • Channelization up to the ds0 level—The following numbers of NxDS0 pseudowires are supported for 16 T1 and E1 built-in ports and 8 T1 and E1 built-in ports.

      Sixteen T1 and E1 built-in ports support the following number of pseudowires:

      • Each T1 port can have up to 24 NxDS0 pseudowires, which add up to a total of up to 384 NxDS0 pseudowires.
      • Each E1 port can have up to 31 NxDS0 pseudowires, which add up to a total of up to 496 NxDS0 pseudowires.

      Eight T1 and E1 built-in ports support the following number of pseudowires:

      • Each T1 port can have up to 24 NxDS0 pseudowires, which add up to a total of up to 192 NxDS0 pseudowires.
      • Each E1 port can have up to 31 NxDS0 pseudowires, which add up to a total of up to 248 NxDS0 pseudowires.
    • Protocol support—All protocols that support Structure-Agnostic TDM over Packet (SAToP) support CESoPSN NxDS0 interfaces.
    • Packet latency—The time required to create packets (from 1000 through 8000 microseconds).
    • CESoPSN encapsulation—The following statements are supported at the [edit interfaces interface-name] hierarchy level:
      • ct1-x/y/z partition partition-number timeslots timeslots interface-type ds
      • ds-x/y/z:n encapsulation cesopsn
    • CESoPSN options—The following statements are supported at the [edit interfaces interface-name cesopsn-options] hierarchy level:
      • excessive-packet-loss-rate (sample-period milliseconds)
      • idle-pattern pattern
      • jitter-buffer-latency milliseconds
      • jitter-buffer-packets packets
      • packetization-latency microseconds
    • Interfaces show commands—The show interfaces interface-name extensive command is supported for t1, e1, and at interfaces.
    • CESoPSN pseudowires—CESoPSN pseudowires are configured on the logical interface, not on the physical interface. So the unit logical-unit-number statement must be included in the configuration at the [edit interfaces interface-name] hierarchy level. When you include the unit logical-unit-number statement, circuit cross-connect (CCC) for the logical interface is created automatically.

    [ ACX Series Universal Access Router Configuration Guide]

Layer 2 and Layer 3 Protocols

  • IPv4 for unicast forwarding—In Junos OS Release 12.2, the ACX Series routers support basic IPv4 for unicast forwarding. The following key forwarding features are supported:
    • Exception handling—All basic exception handling features are supported, including but not limited to option packets, TTL expiry, MTU exceeded condition, redirect condition, and so on. In addition, Internet Control Message Protocol (ICMP) is supported to respond to various exception conditions.
    • ARP—Address Resolution Protocol (ARP) is supported to the full extent available in Junos OS, including but not limited to packet receive and transmit, ARP resolution trigger, and policing of ARP packets through implicit filters.
    • IP fragmentation—Fragmentation is in software and the number of packets fragmented is rate-limited.

    [See TTL Processing on Incoming MPLS Packets and Configuring the Junos OS ARP Learning and Aging Options for Mapping IPv4 Network Addresses to MAC Addresses.]

  • Layer 2 control packets–The forwarding path supports the following types of Layer 2 control packets (excluding Operation, Administration, and Maintenance (OAM) packets) in both directions, receiving and forwarding:
    • Ethernet control packets—ARP, IS-IS, 1588v2, Ethernet Synchronization Messaging Channel (ESMC).

    [See Configuring the Control Word for Layer 2 Circuits.]

  • Host path—The host path to and from the CPU is supported in the following ways:
    • Host-bound traffic, prioritized into multiple queues, to support various levels of traffic.
    • Hardware-based policing used to limit denial-of-service attacks.
    • Protocol and flow-based policing.
    • Code point-based classification and prioritization of packets from the host to the external world.

    [See Path Messages.]

  • Keepalives—The ACX Series routers support high resolution timers of up to 10 ms for driving keepalives for various OAM features, such as Bidirectional Forwarding Detection (BFD) and connectivity fault management (CFM).

    [See Junos OS Interfaces Fundamentals Configuration Guide .]

  • Counters and statistics—Most packet-level and byte-level statistics for various entities in the forwarding path available in Junos OS are supported. The following counters and statistics are supported:
  • Statistics collection and reporting for Gigabit Ethernet interfaces—For Gigabit Ethernet interfaces, Packet Forwarding Engine statistics are disabled by default. To enable Gigabit Ethernet interface statistics, you must specifically configure them. To configure Gigabit Ethernet interface statistics, include the statistics statement at the [edit interfaces interface-name unit logical-unit-number] hierarchy level. To display statistics, issue the show interfaces interface-name (brief | extensive) operational mode command.

    [See Junos OS Ethernet Interfaces Configuration Guide  and Fast Ethernet and Gigabit Ethernet Counters]

  • Scaling and performance—The following scaling and performance features are supported for interfaces and routes on the ACX Series routers:
    • Interfaces—Any logical interface enabled with IPv4 or MPLS is considered a Layer 3 interface. The maximum number of Layer 3 interfaces is 1000.

      Dual-tagged interfaces—The Tag Protocol Identifier (TPID) for dual-tagged interfaces must meet the following conditions:

      • One inner TPID can be specified or used in the system.
      • The standard value of 0x8100 is allowed for the inner TPID.
      • A maximum of four outer standard TPID values, that is, 0x8100, 0x9100, 0x9200, 0x88a8.
    • Route parameters—On the ACX Series routers, all routes use a single, fully qualified match table and a single longest prefix match (LPM) route table. The following numbers assume an exclusive use of these tables for a particular type of route. If there is a mix, the numbers can change. The maximum number of supported routes is the following:
      • For IPv4, 8000 fully qualified match table and 12,000 LPM table.
      • For MPLS, 3000 label lookup entries, 2000 maximum transit unidirectional LSPs, and 1000 maximum Ethernet pseudowires. Only one MPLS lookup table is supported.

      Note: Multicast is not supported on the ACX Series routers.

      Note: With Junos OS, you can partition a single router into multiple logical devices that perform independent routing tasks. The ACX Series routers do not support this feature. Only one logical system is supported, the default logical system. The [edit logical-systems] hierarchy level is not supported.

    • Next-hop parameters—The ACX Series router supports a maximum of 7000 unicast next-hop entries. This number is shared between IPv4, MPLS, and Ethernet pseudowires. The actual number is a little less than 7000 because a few of the next-hop entries are allocated and used internally. An additional 1000 of separate unicast entries are allowed for TDM and ATM pseudowires.
    • Address Resolution Protocol (ARP) parameters—The maximum number of ARP entries is 7000.

      [See Junos OS Interfaces Fundamentals Configuration Guide .]

  • BFD and VCCV—Bidirectional Forwarding Detection (BFD) support for virtual circuit connection verification (VCCV) enables you to configure a control channel for a pseudowire, in addition to the corresponding operations and management functions to be used over that control channel. BFD provides a low-resource mechanism for the continuous monitoring of the pseudowire data path and for detecting data plane failures.

    [See Configuring BFD for VCCV for Layer 2 VPNs, Layer 2 Circuits, and VPLS]

MPLS

  • Label-switching router (LSR)—With MPLS enabled, the ACX Series router can act as an LSR. An LSR processes label-switched packets and forwards packets based on their labels.

    [See Junos OS MPLS Applications Configuration Guide  and MPLS Overview for ACX Series Universal Access Routers.]

  • Label edge router (LER)—The ACX Series router processes IPv4 traffic and pseudowire traffic over the MPLS network. The traffic is processed in both ingress and egress directions. Configuring MPLS on the LER is the same as configuring an LSR.

    [See Junos OS MPLS Applications Configuration Guide  and MPLS Overview for ACX Series Universal Access Routers.]

  • Pseudowire transport service—A pseudowire carries Layer 1 and Layer 2 information over an IP/MPLS network infrastructure. Ethernet, ATM, and TDM pseudowires are supported. Only similar endpoints are supported on the ACX Series routers. For example, T1 to T1, ATM to ATM, and Ethernet to Ethernet.

    [See Pseudowire Overview for ACX Series Universal Access Routers.]

  • Pseudowire redundancy—A redundant pseudowire acts as a backup connection between PE routers and CE devices, maintaining Layer 2 circuits and services after certain types of failures. Pseudowire redundancy improves the reliability of certain types of networks (metro, for example) where a single point of failure could interrupt service for multiple customers. The following pseudowire redundancy features are supported:
    • Pseudowire standby—A standby pseudowire can act as a backup connection between PE routers and CE devices, maintaining Layer 2 circuit and VPLS services after certain types of failures. To configure pseudowire standby, include the backup-neighbor statement at the [edit protocols l2circuit neighbor address interface interface-name] hierarchy level.
    • Protect interface—A backup for the protected interface in case of failure. Network traffic uses the primary interface only so long as the primary interface functions. If the primary interface fails, traffic is switched to the protect interface. To configure the protect interface, specify the protect-interface statement at the [edit protocols l2circuit local-switching interface interface-name] hierarchy level.
    • Hot and cold standby—Hot standby enables swift cutover to the backup or standby pseudowire. Cold standby is the inclusion of the backup-neighbor statement and the absence of the standby statement in the configuration. By default, a pseudowire is not backed up. The following hot standby configurations are supported:
      • Pseudowire hot standby—A pseudowire configured with a backup neighbor is considered a standby pseudowire. When you configure that pseudowire with the standby statement at the [edit protocols l2circuit neighbor address interface interface-name backup-neighbor] hierarchy level, it is considered on hot standby. A pseudowire configured with only the backup-neighbor statement is considered on cold standby.

        When you configure the standby statement on a backed-up pseudowire, traffic flows over both the active and standby pseudowires to the CE device. The CE device drops the traffic from the standby pseudowire, unless the active pseudowire fails. If the active pseudowire fails, the CE device automatically switches to the standby pseudowire.

      • Label-switched path (LSP) hot standby for secondary paths—For an LSP, the hot standby state is meaningful only on secondary LSP paths. Maintaining a path in a hot-standby state enables swift cutover to the secondary path when downstream routers on the current active path indicate connectivity problems. To configure hot standby for an LSP, include the standby statement at the [edit protocols mpls label-switched-path lsp-name secondary] hierarchy level.
    • Ethernet connectivity fault management (CFM)—The following major features of CFM for Ethernet pseudowires only are supported:
      • Connection protection—Fault monitoring using the continuity check protocol. This is a neighbor discovery and health check protocol that discovers and maintains adjacencies at the VLAN or link level.
      • Path protection—Path discovery and fault verification using the linktrace protocol. Similar to IP traceroute, this protocol maps the path taken to a destination MAC address through one or more bridged networks between the source and destination.

      [See Redundant Pseudowires for Layer 2 Circuits and VPLS, Configuring the Protect Interface, Junos OS Layer 2 Configuration Guide , and Junos OS MPLS Applications Configuration Guide .]

  • Control word—The control word is 4 bytes long and is inserted between the Layer 2 protocol data unit (PDU) being transported and the virtual connection label. To configure the control word, include the (control-word | no-control-word) statement at the [edit protocols l2circuit neighbor address interface interface-name] hierarchy level.

    [See Configuring the Control Word for Layer 2 Circuits.]

  • Uniform and pipe mode—In an MPLS network, uniform mode is the default. Uniform mode makes all the nodes that a label-switched path (LSP) traverses visible to nodes outside the LSP tunnel. In contrast, pipe mode acts like a circuit and must be enabled. In pipe mode, when MPLS packets traverse the network, only the LSP ingress and egress points are visible to nodes that are outside the LSP tunnel. To configure pipe mode, include the no-propagate-ttl statement at the [edit protocols mpls] hierarchy level on each router that is in the path of the LSP. The global no-propagate-ttl statement disables time-to-live (TTL) propagation at the router level and affects all RSVP-signaled or LDP-signaled LSPs. Only the global configuration of TTL propagation is supported.

    [See no-propagate-ttl.]

  • Exception packet handling for MPLS—The following types of exception packet handling are supported:
    • Router alert
    • Time-to-live (TTL) expiry value
    • Virtual circuit connection verification (VCCV)

    [See Junos OS MPLS Applications Configuration Guide .]

  • Fast reroute—Fast reroute is supported on ACX Series routers. Fast reroute provides redundancy for a label-switched path (LSP) path.

    [See Junos OS MPLS Applications Configuration Guide .]

  • Link protection—Link protection helps ensure that traffic traversing a specific interface from one router to another can continue to reach its destination in the event that this interface fails.

    [See Link Protection.]

  • Node-link protection—Node-link protection establishes a bypass LSP through a different router altogether.

    [See Node-Link Protection.]

  • MPLS ping and traceroute—The ACX Series routers support MPLS ping and traceroute to the extent supported by Junos OS. Junos OS partially supports LSP ping and traceroute commands based on RFC 4379, Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures. However, Junos OS supports this functionality on LSP transit routers and head-end routers only. If a ping or traceroute command is issued from a router that fully supports RFC 4379, it can propagate correctly on routers running Junos OS.

    [See Pinging LSPs.]

Network Management and Monitoring

  • Extends support for autoinstallation on ACX Series routers—The autoinstallation mechanism for discovering, retrieving, and loading an appropriate configuration is now supported by the ACX Series Universal Access Routers.

    [See ACX Series Autoinstallation Overview..]

Power Management

  • Power over Ethernet (PoE) (ACX2000 Universal Access routers)—PoE is supported based on the IEEE 802.3af and IEEE 802.3at standards. Two ports on the ACX2000 router support PoE interfaces. The PoE interfaces permit electric power, along with data, to be passed over a copper Ethernet LAN cable. The PoE controller keeps track of the PoE power consumption on the router and allocates power to the PoE ports.
    • The PoE interface supports up to 65 W of Power over Ethernet Plus (PoE+).
    • With this new mode of power delivery, all four pairs of wires in the RJ45 cable have an option to deliver up to 65 W power per port provided high-power mode over the four pairs is requested. To enable high-power mode, include the high-power option at the [edit poe management] hierarchy level and include the maximum-power watts statement at the [edit poe interface (interface-name | interface-all)] hierarchy level.
    • Control the PoE interfaces with the following configuration statements and commands:
      • To enable PoE physical interfaces, include the interface statement at the [edit poe] hierarchy level. Specify an individual PoE interface with the interface-name option, or all PoE interfaces with the interface-all option.
      • Disable the PoE interface with the disable statement at the [edit poe interface-name | interface-all] hierarchy level.
      • Configure the PoE interface to gather voltage and power information by including the telemetries statement at the [edit poe interface (interface-name | interface-all)] hierarchy level. Specify the following options for this statement: disable, duration hours, and interval minutes.
      • Display the power consumption with the show poe controller command.
      • Display the configured PoE interfaces with the show poe interface command.

    [See Understanding PoE on ACX Series Universal Access Routers, Junos OS Ethernet Interfaces Configuration Guide , and Junos OS System Basics Configuration Guide .]

Routing Policy and Firewall Filters

  • Firewall features supported on ACX Series Universal Access Routers—Existing Junos OS firewall features are supported without changes to statements or functionality.

    The following is the list of key supported firewall features and any conditions associated with them:

    • Configuration of filters for the following protocol families only: any, ccc, inet, and mpls.
    • Firewall filters applied to a logical interface must have the interface-specific statement included at the respective family hierarchy level.
    • An egress filter must always have the interface-specific statement configured.
    • Configuration of policers and three-color policers.
    • Actions—for example, count, discard, log, and so on.
    • Operational mode commands for firewall filters are supported on the ACX Series routers without changes.

    [See Standard Firewall Filter Match Conditions and Actions on ACX Series Routers Overview.]

  • Filter-based forwarding for routing instances—For IPv4 traffic only, you can use stateless firewall filters in routing instances to control how packets travel in a network. This is called filter-based forwarding.

    You can define a firewall filtering term that directs matching packets to a specified routing instance. This type of filtering can be configured to route specific types of traffic through a firewall or other security device before the traffic continues on its path. To configure a stateless firewall filter to direct traffic to a routing instance, configure a term with the routing-instance routing-instance-name terminating action at the [edit firewall family inet filter filter-name term term-name then] hierarchy level to specify the routing instance to which matching packets will be forwarded. To configure the filter to direct traffic to the master routing instance, use the routing-instance default statement at the [edit firewall family inet filter filter-name term term-name then] hierarchy level.

    [ACX Series Universal Access Router Configuration Guide]

  • Forwarding table filters for routing instances—Forwarding table filter is a mechanism by which all the packets forwarded by a certain forwarding table are subjected to filtering and if a packet matches the filter condition, the configured action is applied on the packet. You can use the forwarding table filter mechanism to apply a filter on all interfaces associated with a single routing instance with a simple configuration. You can apply a forwarding table filter to a routing instance of type forwarding and also to the default routing instance inet.0. To configure a forwarding table filter, include the filter filter-name statement at the [edit firewall family inet] hierarchy level.

    [ACX Series Universal Access Router Configuration Guide]

Routing Protocols

  • Support for Layer 3 VPNs for IPv4 and IPv6 address families—You can configure Layer 3 virtual private network (VPN) routing instances on ACX Series routers at the [edit routing-instances routing-instance-name protocols] hierarchy level for unicast IPv4, multicast IPv4, unicast IPv6, and multicast IPv6 address families. If you do not explicitly specify the address family in an IPv4 or an IPv6 environment, the router is configured to exchange unicast IPv4 or unicast IPv6 addresses by default. You can also configure the router to exchange unicast IPv4 and unicast IPv6 routes in a specified virtual routing and forwarding (VRF) routing instance. If you specify the multicast IPv4 or multicast IPv6 address family in the configuration, you can use BGP to exchange routing information about how packets reach a multicast source, instead of a unicast destination, for transmission to endpoints.

    Only the forwarding and virtual router routing instances support unicast IPv6 and multicast IPv6 address families. Unicast IPv6 and multicast IPv6 address families are not supported for VRF routing instances.

    A VRF routing instance is a BGP and MPLS VPN environment in which BGP is used to exchange IP VPN routes and discover the remote site, and VPN traffic traverses an MPLS tunnel in an IP and MPLS backbone. You can enable an ACX Series router to function as a provider edge (PE) router by configuring VRF routing instances.

    You can configure the following types of Layer 3 routing instances:

    • Forwarding—Use this routing instance type for filter-based forwarding applications.
    • Virtual router—A virtual router routing instance is similar to a VRF instance type, but is used for non-VPN-related applications.
    • VRF—Use the VRF routing instance type for Layer 3 VPN implementations. This routing instance type has a VPN routing table as well as a corresponding VPN forwarding table. For this instance type, there is a one-to-one mapping between an interface and a routing instance. Each VRF routing instance corresponds with a forwarding table. Routes on an interface go into the corresponding forwarding table. This routing instance type is used to implement BGP or MPLS VPNs in service provider networks or in big enterprise topologies.

    [ACX Series Universal Access Router Configuration Guide]

  • Support for Multiprotocol BGP—Multiprotocol BGP (MBGP) is an extension to BGP that enables BGP to carry routing information for multiple network layers and address families. MBGP can carry the unicast routes used for multicast routing separately from the routes used for unicast IP forwarding.

    You can configure MBGP on ACX Series routers for IPv4 and IPv6 address families in the following ways:

    • To enable MBGP to carry network layer reachability information (NLRI) for address families other than unicast IPv4, include the family inet statement at the [edit protocols bgp] or the [edit routing-instances routing-instance-name protocols bgp] hierarchy level.
    • To enable MBGP to carry NLRI for the IPv6 address family, include the family inet6 statement at the [edit protocols bgp] or the [edit routing-instances routing-instance-name protocols bgp] hierarchy level.
    • To enable MBGP to carry Layer 3 virtual private network (VPN) NLRI for the IPv4 address family, include the family inet-vpn statement at the [edit protocols bgp] or the [edit routing-instances routing-instance-name protocols bgp] hierarchy level.
    • To enable MBGP to carry Layer 3 VPN NLRI for the IPv6 address family, include the family inet6-vpn statement at the [edit protocols bgp] or the [edit routing-instances routing-instance-name protocols bgp] hierarchy level.
    • To enable MBGP to carry multicast VPN NLRI for the IPv4 address family and to enable VPN signaling, include the family inet-mvpn statement at the [edit protocols bgp] or the [edit routing-instances routing-instance-name protocols bgp] hierarchy level.
    • To enable MBGP to carry multicast VPN NLRI for the IPv6 address family and to enable VPN signaling, include the family inet6-mvpn statement at the [edit protocols bgp] or the [edit routing-instances routing-instance-name protocols bgp] hierarchy level.

    [ACX Series Universal Access Router Configuration Guide]

Software Architecture

  • ACX Series router architecture—The ACX Series router is a single-board router with a built-in Routing Engine and one Packet Forwarding Engine that has one Flexible PIC Concentrator (FPC 0). Because there is no switching fabric, the single Packet Forwarding Engine takes care of packet forwarding.
    • Routing Engine—Provides Layer 3 routing services and network management.
    • Packet Forwarding Engine—Performs Layer 2 and Layer 3 packet switching, route lookups, and packet forwarding.

      [See ACX Series Universal Access Router Overview.]

  • Packet Forwarding Engine management—The request chassis feb restart slot slot-number command is introduced to restart the specified Forwarding Engine Board (FEB). When you enter this command, you are provided feedback on the status of your request. For example:
    user@host> request chassis feb restart slot 0
FEB will be restarted NOW.

    [See request chassis feb.]

  • Dual-speed Gigabit Ethernet interface—The Gigabit Ethernet ports on the router have the capacity to work as a 1- or 10-Gigabit Ethernet interface, depending on the type of small form-factor pluggable (SFP) transceiver inserted. When you insert an SFP+ transceiver, the interface works at the 10-gigabit speed. When you insert an SFP transceiver, the interface works at the 1-gigabit speed. Configuration is not required because the speed is determined automatically based on the type of inserted SFP transceiver. The dual-speed interface is automatically created with the xe prefix, for example, xe-4/0/0.

    The same configuration statements are used for both speeds, and CoS parameters are scaled as a percentage of the port speed. To configure a dual-speed Gigabit Ethernet interface, include the interface xe-fpc/pic/port statement at the [edit interfaces] hierarchy level. To display the interface speed and other details, issue the show interfaces command.

    [See Understanding Interfaces on ACX Series Universal Access Routers.]

  • SNMP and MIB support—The ACX Series routers support all existing MIBs that identify all the different components of the chassis—for instance, the power supply. Existing MIB support is defined in Standard SNMP MIBs Supported by Junos OS and Enterprise-Specific MIBs and Supported Devices.
  • Memory utilization—The show chassis routing-engine and the show chassis feb commands can be used to find the memory allocated for each of the Routing Engine and Packet Forwarding Engine components.

    [See show chassis routing-engine and show chassis feb.]

  • System snapshot support—The request system snapshot command enables you to create a copy of the currently running software on another media—for example, a universal serial bus (USB) storage device, the active slice of a dual-root partitioned router, or the alternate slice of a dual-root partitioned router. Typically, this command is used prior to the upgrade of the software image on the dual internal NAND flash device (with the da0s1 or da0s2 slices) or to remedy a bad image, thereby preventing the bad image from rendering the system useless. A snapshot to another media ensures that the device can boot from the other media in case the system does not boot from the current image.

    [See Understanding System Snapshot on an ACX Series Router, Example: Taking a Snapshot of the Software and Configuration, and request system snapshot (ACX Series).]

Timing and Synchronization

  • Timing and synchronization support at the chassis level—All existing Junos OS timing and synchronization features are supported at the [edit chassis synchronization] hierarchy level without changes to statements or functionality, except for the external-a and the external-b statements, which are not supported on the ACX Series routers. Instead of the external-a and the external-b statements, the ACX Series routers support the new bits and gps statements at the [edit chassis synchronization source] hierarchy level.
    • bits—The external building-integrated timing supply (BITS) device is connected to the router’s T1 or E1 BITS interface, which upon configuration becomes a candidate for selection as the clock source by the clock source selection algorithm.
    • gps—The 10-MHz clock input received from the Global Positioning System (GPS) is considered one of the candidate sources for chassis synchronization by the clock source selection algorithm.

      Both the bits and gps statements include the following options:

      • priority number—Specify a priority level between 1 and 5. When not specified, gps has a higher default priority than bits, and bits has a higher default priority than other Gigabit Ethernet, 10-Gigabit Ethernet, T1, or E1 clock sources, which have the lowest default priority.

      • quality-level (prc | prs |sec | smc | ssu-a | ssu-b | st2 | st3 | st3e | st4 | stu | tnc)—Specify the expected quality of the incoming clock on this source. Specific quality-level options are valid depending on the configured network-option: option-1 or option-2 at the [edit chassis synchronization] hierarchy level.

        • Both option I and option II SSM quality levels (QL) are supported:

          • Both option-1 and option-2 Synchronization Status Message (SSM) quality levels (QL) are supported:
          • For option-2, the default QL for external clocks is QL_STU whether or not QL is enabled.
      • request force-switch—Force a switch to the source provided that the source is enabled and not locked out. Only one configured source can be force-switched.
      • request lockout—A lockout can be configured for any source. When a lockout is configured for a source, that source will not be considered by the selection process.

      [See Clock Sources for the ACX Series Universal Access Routers, bits, and gps.]

  • T1 or E1 BITS interface (ACX2000 router)—The ACX2000 router has a T1 or E1 building integrated timing source (BITS) interface that you can connect to an external clock. After you connect the interface to the external clock, you can configure the BITS interface so that the BITS interface becomes a candidate source for chassis synchronization to the external clock. The frequency of the BITS interface depends on the Synchronous Ethernet equipment (EEC) slave clock selected with the network-option statement at the [edit chassis synchronization] hierarchy level.
    • option-1—EEC-Option 1 applies to Synchronous Ethernet equipment optimized for 2048 Kbps. With this option, the BITs interface operates at the speed of an E1 interface.
    • option-2—EEC-Option 2 applies to Synchronous Ethernet equipment optimized for 1544 Kbps. With this option, the BITS interface operates at the speed of a T1 interface.

    To configure the BITS interface as the candidate source for synchronization, include the bits statement and options at the [edit chassis synchronization source] hierarchy level.

    [See External Clock Synchronization Overview for ACX Series Routers and source (Chassis Synchronization).]

  • Global Positioning System (GPS)—GPS is a navigation aid system that uses signals from satellites to calculate the actual position of a GPS-capable receiver. These signals are not only used for determining the position of the receiver on Earth but also as a very accurate time base. There are GPS receivers with 10-MHz clock frequency output synchronized to a GPS satellite. The ACX Series router has a SubMinature version B (SMB) connector that can take 10-MHz sine-wave input from a GPS receiver. To configure this 10-MHz clock from a GPS receiver as a candidate clock source for chassis synchronization, include the gps statement and options at the [edit chassis synchronization source] hierarchy level.

    [See Configuring External Clock Synchronization for ACX Series Routers and gps.]

  • Automatic clock selection—In automatic clock selection, the system chooses up to two best upstream clock sources. The system then uses the clock recovered from one of the sources to lock the chassis clock. If an upstream clock with acceptable good quality is not available or if the system is configured in free-run mode, the system uses the internal oscillator. The following automatic clock selection features are supported for Synchronous Ethernet, T1 or E1 line timing sources, and external inputs:

    Note: Automatic clock selection does not apply to the IEEE 1588v2 recovered clock.

    • Basis of automatic clock selection—Automatic clock selection of the best quality clock source is based on the Ethernet Synchronization Message Channel (ESMC) Synchronization Status Message (SSM) quality level, the configured quality level, and the priority. To configure the clock mode, include the clock-mode statement with the free-run option or the auto-select option at the [edit chassis synchronization] hierarchy level. When the free-run option is configured, the chassis is locked to the free-running local oscillator, which is the Stratum 3E oscillator. The auto-select option enables the clock source selection algorithm to run.

      [See clock-mode.]

    • Clock source selection algorithm—The clock source selection algorithm is triggered by the following events:
      • Signal failure detected on the currently selected source.
      • Changes in the received ESMC SSM quality level.
      • Configuration changes. For example, the addition or deletion of a clock source, a change to the quality level mode, and so on.

      Automatic clock selection supports two modes on the ACX Series router: QL enabled and QL disabled. To configure QL mode, include the quality-mode-enable statement at the [edit chassis synchronization] hierarchy level.

      • QL disabled—The default setting is disable, which means that when the quality-mode-enable statement is not configured, quality level is disabled. In this mode, the best clock is selected based on the configured ESMC SSM quality level. If the quality levels of the configured clocks are equal, the clock selection is based on the configured priority. If both the configured quality levels and priority are equal, one of the sources is randomly selected.
      • QL enabled—In this mode, the best clock is selected based on the incoming ESMC SSM quality level as long as the incoming quality level is at least as good as the source’s configured quality level. If the quality levels are equal, the clock selection is based on the configured priority. If both the received quality level and the priority are equal, one of the sources is selected randomly.
    • Configured or received clock selection—The selection-mode (configured-quality | received-quality) statement specifies whether the clock source selection algorithm should use the configured or received ESMC SSM quality level for clock selection. In both the selection modes, the interface qualifies for clock source selection only when the received ESMC SSM quality level on the interface is equal to or greater than the configured ESMC SSM quality level for the interface.

      When the selection-mode statement is set as configured-quality, the clock source selection algorithm uses the ESMC SSM quality level configured for a clock source.

      When the selection-mode statement is set as received-quality, the clock source selection algorithm uses the ESMC SSM quality level received on the interface that is configured as a clock source.

      Note: For the selection-mode statement configuration to take effect, you must set the quality-mode-enable statement at the [edit chassis synchronization] hierarchy level.

      [See Automatic Clock Selection Overview, Clock Sources for the ACX Series Universal Access Routers, and synchronization (ACX Series).]

  • Synchronous Ethernet (ACX2000 router)—Synchronous Ethernet is a physical layer frequency transfer technology modeled after synchronization in SONET/SDH. Traditional Ethernet nodes, which do not support Synchronous Ethernet, do not carry synchronization from one node link to another. Synchronous Ethernet capable nodes, however, can synchronize their chassis clock to a clock recovered from an interface connected to an upstream clock master. After which, the clock is used to time data sent to downstream clock slaves, forming a synchronization trail from a primary reference clock (PRC) to Ethernet equipment clocks (EECs) and transferring frequency synchronization along the trail.

    The ITU G.8264 specification defines the Synchronization Status Message (SSM) protocol and its format for Synchronous Ethernet to ensure interoperability between Synchronous Ethernet equipment used for frequency transfer—for example, SONET/SDH. Synchronous Ethernet provides stable frequency synchronization to a PRC and is not affected by load on the network. However, it requires that all the nodes from the PRC to the last downstream node are Synchronous Ethernet capable. Synchronous Ethernet is a recommended technology for mobile networks that require frequency-only synchronization—for example, 2G or 3G base stations.

    [See Synchronous Ethernet Overview on the ACX Series Universal Access Routers.]

  • Precision Timing Protocol (PTP), also known as IEEE 1588v2—PTP synchronizes clocks between nodes in a network, thereby enabling the distribution of an accurate clock over a packet-switched network. This synchronization is achieved through packets that are transmitted and received in a session between a master clock and a slave clock. The master clock is external to the ACX Series router, for example, a TCA Series Timing Client or an MX Series router.

    Most existing PTP statements are supported without changes in functionality, see [edit protocols ptp] Hierarchy Level for details about particular statements. The following new PTP statements are supported:

    • ipv4-dscp number—Specifies the value used as the DiffServ code point (DSCP) value for all PTP IPv4 packets originated by the router. To configure the DSCP value, include the ipv4-dscp number statement at the [edit protocols ptp] hierarchy level.

      [See ipv4-dscp.]

    • announce-interval announce-interval-value—This value specifies the rate of announce messages that a PTP slave clock requests from the master clock during a unicast negotiation session. The announce interval is configured on the slave clock. To configure the announce interval, include the announce-interval announce-interval-value statement at the [edit protocols ptp slave] hierarchy level. The configuration of the announce-interval statement is effective only when the unicast-negotiation statement is also configured at the [edit protocols ptp] hierarchy level.

      [See announce-interval.]

    • grant-duration interval—When unicast negotiation is enabled, the local PTP slave clock requests announce, sync, and delay-response messages from the master clock. In each request, the slave clock asks for the packets to be sent at a specified rate, and it provides a duration for which the rate is valid. The grant-duration value is specified in seconds. The default grant duration is 3600 seconds or 1 hour. To configure the grant duration, include the grant-duration interval statement at the [edit protocols ptp slave] hierarchy level.

      [See grant-duration.]

    • asymmetry number—A compensating value for networks in which there is path asymmetry between the 1588v2 slave and master clocks. Specify a positive or negative value that is added to the path delay value from the slave clock to the master clock, making the delay symmetric and equal to the path from the master clock to the slave clock. The asymmetry value is in nanoseconds and can vary from minus (–) 100 milliseconds to 100 milliseconds, allowing compensation for up to 1/10 of a second of path asymmetry. To configure an asymmetrical value, include the asymmetry number statement at the [edit protocols ptp slave interface interface-name unicast-mode clock-source ip-address local-ip-address ip-address] hierarchy level.

      [See asymmetry.]

    • sync-interval interval—Requested log mean interval between sync messages. The sync-interval is configured on the slave clock and specifies the rate at which sync messages are requested to be sent from the master clock to the slave clock. The specified value is the log2 value of the requested sync packet rate. Because the accepted value varies from –6 to 0, the specified packet rate will be from 2^-6 to 2^0 or from 64 packets per second to 1 packet per second.

      The configuration of the sync-interval statement is effective only when the unicast-negotiation statement is also configured at the [edit protocols ptp] hierarchy level.

      [See sync-interval.]

    The following key PTP features are supported:

    • Ordinary clock (slave only)—The PTP ordinary slave clock estimates time offset from the PTP master clock and tries to align its own time and frequency with that of the master clock. ACX Series routers support the IEEE 1588v2 compliant ordinary slave clock. To configure a slave clock, include the slave statement and options at the [edit protocols ptp] hierarchy level.
    • PTP over UDP over IPv4—The IEEE1588v2 standard specifies different transport protocols for carrying PTP packets. For example, PTP over Ethernet, PTP over UDP over IPv4, and PTP over UDP over IPv6. The ACX Series routers support PTP over UDP over IPv4.
    • Unicast mode (IPv4 on Gigabit Ethernet interfaces only)—Unicast mode is a user-to-user protocol used to send a datagram to a single recipient. Unicast mode is used for transporting PTP messages. To configure unicast mode on an interface, include the unicast-mode statement at the [edit protocols ptp slave interface interface-name] hierarchy level.

      [See Precision Timing Protocol (PTP) on ACX Series Universal Access Routers, [edit protocols ptp] Hierarchy Level, Example: Configuring an Ordinary Slave Clock With Unicast-Negotiation, and Example: Configuring an Ordinary Slave Clock Without Unicast-Negotiation.]

Modified: 2015-08-04

Previous Page Next Page