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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