CoS Support on QFX Series Switches and EX4600 Line of Switches

Juniper Networks data center switches differ in some aspects of class-of-service (CoS) support because of differences in the way the switches are used in networks, and because of hardware differences such as different chipsets or different interface capabilities.

This topic summarizes CoS support on QFX Series switches, the EX4600 line of switches, and QFabric systems.

CoS Feature Support

Table 1: QFX10000, QFX5000 Line, and EX4600 Line CoS Features
Feature	QFX10000	QFX 5000 Line, EX4600 Line	QFX5220/QFX5130/QFX5700
Class of service (CoS)—Class-based queuing with prioritization	Yes	Yes	Yes
CoS—Separate unicast and multi-destination classifiers, forwarding classes, and output queues	No	Yes	Yes (except multi-destination classifiers. Use firewall filters to classify multicast traffic.)
CoS—Shared unicast and multidestination classifiers, forwarding classes, and output queues	Yes	No	No
CoS support on link aggregation groups (LAGs)	Yes	Yes	Yes
Enhanced transmission selection (ETS) hierarchical port scheduling	Yes (starting in Junos OS Release 17.3)	QFX5100, QFX 5110, EX4600—Yes QFX5120, QFX5200, QFX5210, EX4650—No	No
Port scheduling	Yes	Yes, except EX4600	Yes
Queue shaping	Yes Note: Uses the `transmit-rate` statement with the `exact` option.	Yes Note: Uses the `shaping-rate` statement.	Yes
Explicit congestion notification (ECN)	Yes	Yes	Yes
Priority-based flow control (PFC)	Yes	Yes	Yes
Re-marking of bridged packets	Yes	Yes	Yes
Weighted random early detection (WRED) packet drop profiles and tail drop	Yes	Yes	Yes
802.3X Ethernet PAUSE	Yes	Yes	No
Layer 2 ingress packet classification and egress rewrite rules	Yes	Yes	Yes
MPLS EXP ingress packet classification and egress rewrite rules	Yes	Yes	No
Layer 3 ingress packet classification and egress rewrite rules	Yes	Yes	Yes (Both IPv4 and IPv6 traffic must share the same classifier.)
Virtual output queue (VOQ) architecture	Yes	No	No
Software shared buffer configurability	No (uses VOQ)	Yes	Yes, with the following restrictions: `multicast` partition is not supported in the egress shared buffer pool. See buffer-partition (Egress). `lossy` and `lossless` partitions must have the same percentage values for ingress and egress shared buffer pools.
Shared buffer Alpha configurability	No	Yes	Yes
Buffer monitoring	No	Yes	Yes
CoS command to detect the source of RED-dropped packets	Yes	No	No

Classifier and Rewrite Rule Ethernet Interface Type Support

The next two tables in this topic list CoS Ethernet support for classifiers and rewrite rules on different interface types for QFX10000 switches (Table 2), and for QFX5100, QFX5110, QFX5120, QFX5200, QFX5210, QFX5220, EX4600, and EX4650 switches (Table 3).

On QFX10000 switches, you cannot apply classifiers or rewrite rules to Layer 2 or Layer 3 physical interfaces. You can apply classifiers and rewrite rules only to Layer 2 logical interface unit 0. You can apply different classifiers and rewrite rules to different Layer 3 logical interfaces. Table 2 shows on which interfaces you can configure and apply classifiers and rewrite rules.

Table 2: Ethernet Interface Support for Classifier and Rewrite Rule Configuration (QFX10000 Switches)
CoS Classifiers and Rewrite Rules	Layer 2 Physical Interfaces	Layer 2 Logical Interface (Unit 0 Only)	Layer 3 Physical Interfaces	Layer 3 Logical Interfaces
Fixed classifier	No	Yes	No	Yes
DSCP classifier	No	Yes	No	Yes
DSCP IPv6 classifier	No	Yes	No	Yes
IEEE 802.1p classifier	No	Yes	No	Yes
EXP classifier	No	Yes	No	Yes
DSCP rewrite rule	No	Yes	No	Yes
DSCP IPv6 rewrite rule	No	Yes	No	Yes
IEEE 802.1p rewrite rule	No	Yes	No	Yes
EXP rewrite rule	No	Yes	No	Yes

On QFX5100, QFX5110, QFX5120, QFX5200, QFX5210, EX4600, and EX4650 switches, you cannot apply classifiers or rewrite rules to Layer 2 physical interfaces or to Layer 3 logical interfaces. Table 3 shows on which interfaces you can configure and apply classifiers and rewrite rules.

Table 3: Ethernet Interface Support for Classifier and Rewrite Rule Configuration (QFX5100, QFX5110, QFX5120, QFX5200, QFX5210, EX4600, EX4650 Switches)
CoS Classifiers and Rewrite Rules	Layer 2 Physical Interfaces	Layer 2 Logical Interface (Unit 0 Only)	Layer 3 Physical Interfaces (If at Least One Logical Layer 3 Interface Is Defined)	Layer 3 Logical Interfaces
Fixed classifier	No	Yes	Yes	No
DSCP classifier	No	Yes	Yes	No
DSCP IPv6 classifier	No	Yes	Yes	No
IEEE 802.1p classifier	No	Yes	Yes	No
EXP classifier	Global classifier, applies only to all switch interfaces that are configured as `family mpls`. Cannot be configured on individual interfaces.
DSCP rewrite rule	No	Yes	Yes	No
DSCP IPv6 rewrite rule	No	Yes	Yes	No
IEEE 802.1p rewrite rule	No	Yes	Yes	No
EXP rewrite rule	No	Yes	Yes	No

Note:

IEEE 802.1p mutidestination and DSCP multidestination classifiers are applied to all interfaces and cannot be applied to individual interfaces. No DSCP IPv6 multidestination classifier is supported. IPv6 multidestination traffic uses the DSCP multidestination classifier.

On QFX5220, QFX5130, and QFX5700 switches, you cannot apply classifiers or rewrite rules to Layer 2 or Layer 3 physical interfaces. Table 4 shows on which interfaces you can configure and apply classifiers and rewrite rules.

Table 4: Ethernet Interface Support for Classifier and Rewrite Rule Configuration (QFX5220, QFX5130, and QFX5700 Switches)
CoS Classifiers and Rewrite Rules	Layer 2 Physical Interfaces	Layer 2 Logical Interfaces	Layer 3 Physical Interfaces	Layer 3 Logical Interfaces
Fixed classifier	No	Yes	No	Yes
DSCP classifier	No	Yes	No	Yes
DSCP IPv6 classifier	No	No	No	No
IEEE 802.1p classifier	No	Yes	No	Yes
EXP classifier	No	No	No	No
DSCP rewrite rule	No	Yes	No	Yes
DSCP IPv6 rewrite rule	No	No	No	No
IEEE 802.1p rewrite rule	No	Yes	No	Yes
EXP rewrite rule	No	No	No	No

Note:

QFX5220, QFX5130, and QFX5700 switches do not support DSCP IPV6 classifiers and rewrite rules. Instead, attach DSCP classifiers and rewrite rules on family inet6.

CoS Operational Comparison Between QFX5100, QFX5120, QFX5130, QFX5200, QFX5210, QFX5220, and QFX5700 Switches

CoS feature support is mostly the same for QFX5100, QFX5120, QFX5130, QFX5200, QFX5210, QFX 5220, QFX5700 switches, but there are some CoS operational differences due to different chipsets among these platforms. Table 5 details both the similarities and differences for CoS on QFX5100, QFX5120, QFX5200, QFX5210, and QFX5220 switches.

Table 5: CoS Operational Comparison Between QFX5100, QFX5120, QFX5130, QFX5200, QFX5210, QFX5220, and QFX5700 Switches
CoS Feature	QFX5100	QFX5120	QFX5130/QFX5700	QFX5200	QFX5210	QFX5220	Change in Operation
Memory Management	Central memory management unit (MMU) shared by all ports	Central MMU shared by all ports	Ingress traffic manager (ITM) architecture – Buffers divided equally among 2 ITMS	Crosspoint architecture with quad pipe	Crosspoint architecture with quad pipe	ITM architecture – Buffers divided equally among 2 ITMS	ITM architecture requires special buffer management.
Pipes	2	2	8	4	4	8	No customer visible change.
Cell Accounting	Global access pipes	Global access pipes	Local to ITM (66MB/ITM)	Local to Cross point (4MB / cross point)	Local to Cross point (10.5MB / cross point)	Local to ITM (32MB/ITM)	No customer visible change.
Shared Buffer	60k Cells (Each cell 208Bytes), 12MB	About 131K Cells (Each cell 256 Bytes), 32MB	About 543K cells (Each cell 254 bytes), 132MB	(QFX5200-32C) 80K Cells (Each cell 208 Bytes), 16MB (QFX5200-48Y) 108K Cells (Each cell 208 Bytes), 22MB	About 210K Cells (Each cell 208 Bytes), 42MB	About 264K Cells (Each cell 254 Bytes), 64MB	No customer visible change, except QFX5200 and QFX5210 support larger packet buffer space than QFX5100.
Shared buffer pool per pipe	4 pools per pipe	4 pools per pipe	4 pools per pipe	4 pools per pipe	4 pools per pipe	4 pools per pipe	N/A
Queuing and Scheduling	LLS and three- level hierarchy	Fixed hierarchical scheduling (FHS) and two-level hierarchy	Fixed hierarchical scheduling (FHS) and two-level hierarchy	Fixed hierarchical scheduling (FHS) and two-level hierarchy	Fixed hierarchical scheduling (FHS) and two-level hierarchy	Fixed hierarchical scheduling (FHS) and two-level hierarchy	ETS and FC-Set are not supported on QFX5120, QFX5130, QFX5200, QFX5210, QFX5220, and QFX5700 due to FHS.
# Unicast Queues	8	8	8	8	8	8	N/A
# Multicast Queues	4	2	4	2	2	2	N/A
CPU Queues	44	44	44	44	44	44	N/A
Host Path Scheduling	48 queues directly attached to port	48 queues attached to L0	48 queues attached to L0	48 queues attached to L0	48 queues attached to L0	48 queues attached to L0	No customer visible change.
FC2Q	4 profiles	4 profiles	4 profiles	4 profiles	4 profiles	4 profiles	N/A
DSCP classifier table	128 profiles	128 profiles	64 profiles	128 profiles	128 profiles	64 profiles	N/A
802.1p classifier table	64 profiles	64 profiles	64 profiles	64 profiles	64 profiles	64 profiles	No customer visible change. SDK API change just affects software development effort.
PFC	Common headroom buffer	Common headroom buffer	Per ITM headroom buffer	Per pipe headroom buffer	Per pipe headroom buffer	Per ITM headroom buffer	Available and used head room buffer is maintained separately for each pipe on QFX5200 and QFX5210.
Rewrite	128 profiles	128 profiles	128 profiles	128 profiles	128 profiles	128 profiles	No customer visible change. SDK API change just affects software development effort.
WRED	128 profiles per pipe	128 profiles per pipe	128 profiles per pipe	128 profiles per pipe	128 profiles per pipe	128 profiles per pipe	N/A
Queueing Levels	Four levels physical queue level, logical queue level, CoS level, and port level	Three levels, logical queue level, CoS level, and port level.	Three levels, logical queue level, CoS level, and port level.	Three levels, logical queue level, CoS level, and port level.	Three levels, logical queue level, CoS level, and port level.	Three levels, logical queue level, CoS level, and port level.	N/A
Multidestination Traffic	Default scheduler map reserves 20% bandwidth for multicast and 80% of unicast traffic reserved between BE, FCoE, NoLoss and NC traffic types.	Same as QFX5100 switches	By default all multicast traffic mapped to Q8. Q8 is given 20% bandwidth in default scheduler. To classify multicast traffic to different queues (Q9,10,11) use firewall filters.	Each level 0 node is receiving both multicast and unicast traffic, so it is not possible to differentiate at the port level to apply shaping on multicast traffic.	Same as QFX5200 switches	By default all multicast traffic mapped to Q8. Q8 is given 20% bandwidth in default scheduler. To classify multicast traffic to different queue (Q9) use firewall filters.	N/A

The following limitations on QFX5200 and QFX5210 switches do not exist on QFX5100 switches.

CoS flexible hierarchical scheduling (ETS) is not supported on QFX5200 or QFX5210 switches.
QFX5200 and QFX5210 switches support only one queue with strict-high priority because these switches do not support flexible hierarchical scheduling.

Note:
QFX5100 switches support multiple queues with strict-high priority when you configure a forwarding class set.
QFX5200 CoS policers do not support global management counters accessed by all ports. Only management counters local to a pipeline are supported—this means that QFX5200 management counters work only on traffic received on ports that belong to the pipeline in which the counter is created.
Due to the cross-point architecture on QFX5200 and QFX5210 switches, all buffer usage counters are maintained separately. When usage counters are displayed with the command show class-of-service shared-buffer, various pipe counters are displayed separately.
On QFX5200 and QFX5210 switches, port schedulers are supported instead of FC-SET.
On QFX5200 and QFX5210 switches, it is not possible to group multiple forwarding classes into a forwarding class set (fc-set) and apply output traffic control profile on the fc-set. ETS for an fc-set is not supported. Because each L0 node schedules both the unicast and multicast queue of L1 node, it is not possible to differentiate multicast and unicast traffic at the port level and apply minimum bandwidth between unicast and multicast. It can only be supported at CoS level L0.
Because QFX5200 and QFX5210 switches do not support flexible hierarchical scheduling, it is not possible to apply a traffic control profile for a group of forwarding classes.

QFX10000 Switch Classifier and Rewrite Rule Support (Scaling)

You can configure enough classifiers on QFX10000 switches to handle most, if not all, network scenarios. Table 6 shows how many of each type of classifiers you can configure, and how many entries you can configure per classifier.

Table 6: Classifier Support by Classifier Type on QFX10000 Switches
Classifier Type	Default Classifier Name	Maximum Number of Classifiers	Maximum Number of Entries per Classifier
IEEE 802.1p (Layer 2)	ieee8021p-default (for ports in trunk mode) ieee8021p-untrust (for ports in access mode)	64	16
DSCP (Layer 3)	dscp-default	64	64
DSCP IPv6 (Layer 3)	dscp-ipv6-default	64	64
EXP (MPLS)	exp-default	64	8
Fixed	There is no default fixed classifier	8	16

The number of fixed classifiers supported (8) equals the number of supported forwarding classes (fixed classifiers assign all incoming traffic on an interface to one forwarding class).

There are no default rewrite rules. You can configure enough rewrite rules on QFX10000 switches to handle most, if not all, network scenarios. Table 7 shows how many of each type of rewrite rule you can configure, and how many entries you can configure per rewrite rule.

Table 7: Rewrite Rule Support by Rewrite Rule Type on QFX10000 Switches
Rewrite Rule Type	Maximum Number of Rewrite Rule Sets	Maximum Number of Entries per Rewrite Rule Set
IEEE 802.1p (Layer 2)	64	128
DSCP (Layer 3)	32	128
DSCP IPv6 (Layer 3)	32	128
EXP (MPLS)	64	128

ON THIS PAGE

CoS Support on QFX Series Switches and EX4600 Line of Switches

CoS Feature Support

Classifier and Rewrite Rule Ethernet Interface Type Support

CoS Operational Comparison Between QFX5100, QFX5120, QFX5130, QFX5200, QFX5210, QFX5220, and QFX5700 Switches

QFX10000 Switch Classifier and Rewrite Rule Support (Scaling)

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