Supported Platforms
Understanding Interfaces on ACX Series Universal Access Routers
The ACX Series routers support time-division multiplexing (TDM) T1 and E1 interfaces and Ethernet (10GbE, 100GbE, 1000GbE copper, and 1GbE and10GbE fiber) interfaces to support both the legacy and evolution needs of the mobile network. Support for Power over Ethernet (PoE+) at 65 watts per port mitigates the need for additional electrical cabling for microwaves or other access interfaces.
The ACX Series routers support the following:
- TDM T1 and E1 ports:
- The ACX1000 router contains eight T1 or E1 ports.
- The ACX2000 router contains 16 T1 or E1 ports.
- Inverse Multiplexing for ATM (IMA)
- Gigabit Ethernet ports:
- The ACX1000 router contains eight Gigabit Ethernet ports. The ACX1000 router also supports either four RJ45 (Cu) ports or installation of four Gigabit Ethernet small form-factor pluggable (SFP) transceivers.
- The ACX2000 router contains 16 Gigabit Ethernet ports and two PoE ports. The ACX2000 router also supports installation of two Gigabit Ethernet SFP transceivers and two 10-Gigabit Ethernet SFP+ transceivers.
T1 and E1 Time-Division Multiplexing (TDM) Interfaces
On the ACX Series routers, existing Junos OS TDM features are supported without changes to statements or functionality. The following key TDM features for T1 (ct1) interfaces and E1 (ce1) interfaces are supported:
- T1 and E1 channelization
- T1 and E1 encapsulation
- Alarms, defects, and statistics
- External and internal loopback
- TDM class of service (CoS)
T1 and E1 mode selection is at the PIC level. To set the T1 or E1 mode at the PIC level, include the framing statement with the t1 or e1 option at the [chassis fpc slot-number pic slot-number] hierarchy level. All ports can be T1 or E1. Mixing T1s and E1s is not supported.
T1 or E1 BITS Interface (ACX2000)
The ACX2000 router has a T1 or E1 building-integrated timing supply (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 slave clock (EEC) selected with the network-option statement at the [edit chassis synchronization] hierarchy level.
 | Note: The ACX1000 router does not support the BITS interface. |
Inverse Multiplexing for ATM (IMA)
Defined by the ATM Forum, IMA specification version 1.1 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 eight links per bundle and 16 bundles per PIC are supported. The following key IMA features are supported:
- IMA Layer 2 encapsulation
- ATM CoS
- ATM policing and shaping
- Denied packets counter in the output for the show interfaces at-fpc/pic/port extensive command
Gigabit Ethernet interfaces
On the ACX Series routers, existing Junos OS Ethernet features are supported without changes to statements or functionality. The following key features are supported:
- Media type specification (ACX1000 router with Gigabit Ethernet SFP and RJ45 interfaces)
- Autonegotiation for RJ45 Gigabit Ethernet interfaces
- Event handling of SFP insertion and removal
- Explicit disabling of the physical interface
- Flow control
Note: The ACX Series router does not support flow control based on PAUSE frames.
- Loopback
- Loss of signal (LOS) alarm
- Media access control (MAC) layer features
- Maximum transmission unit (MTU)
- Remote fault notification for 10-Gigabit Ethernet interfaces
- Statistics collection and handling
- Power over Ethernet (PoE) (ACX2000 router)
- High power mode
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.
