The Class of Service Quick Configuration pages allow you to configure most of the JUNOS CoS components for the IPv4 and MPLS traffic on a J-series or SRX-series device. You can configure forwarding classes for transmitting packets, define which packets are placed into each output queue, schedule the transmission service level for each queue, and manage congestion using a random early detection (RED) algorithm. After defining the CoS components you must assign classifiers to the required physical and logical interfaces.
This section contains the following topics:
Using the Class of Service Quick Configuration pages, you can configure various CoS components individually or in combination to define particular CoS services. For a description of different CoS components, see JUNOS CoS Components.
Figure 97 shows the initial Quick Configuration page for CoS that displays the CoS components.
Figure 97: Initial Class of Service Quick Configuration Page

To configure CoS components with Quick Configuration:
Figure 98 shows the initial Quick Configuration page for defining aliases for CoS values, and Table 248 describes the related fields. By defining aliases you can assign meaningful names to a particular set of bit values and refer to them when configuring CoS components. For more information about CoS values and aliases, see Default CoS Values and Aliases.
Figure 98: CoS Value Aliases Quick Configuration Page

Table 248: CoS Value Aliases Quick Configuration Pages Summary
Figure 99 shows the initial Quick Configuration page for defining forwarding classes and assigning them to queues, and Table 249 describes the related fields. By assigning a forwarding class to a queue number, you affect the scheduling and marking of a packet as it transits a J-series Services Router or an SRX-series services gateway. For more information about forwarding classes and queues, see JUNOS CoS Components.
Figure 99: Forwarding Classes Quick Configuration Page

Table 249: Forwarding Classes Quick Configuration Pages Summary
Figure 100 shows the initial Quick Configuration page for defining classifiers, and Table 250 describes the related fields. Classifiers examine the CoS value or alias of an incoming packet and assign it a level of service by setting its forwarding class and loss priority. For more information about classifiers, see Default Behavior Aggregate Classifiers.
Figure 100: Classifiers Quick Configuration Page

Table 250: Classifiers Quick Configuration Page Summary
Field |
Function |
Your Action |
|---|---|---|
| Classifier Summary | ||
DSCP |
Allows you to define classifiers for DSCP IPv4 values. |
To define a classifier for a DSCP code point value, click DSCP. |
DSCP IPv6 |
Allows you to define classifiers for DSCP IPv6 values. |
To define a classifier for a DSCP IPv6 value, click DSCP IPv6. |
MPLS EXP |
Allows you to define classifiers for MPLS experimental (EXP) bits. |
To define a classifier for a set of MPLS EXP bits, click MPLS EXP. |
IPv4 Precedence |
Allows you to define classifiers for IPv4 precedence values. |
To define a classifier for an IP precedence value, click IPv4 Precedence. |
Classifier Name |
Displays the names of classifiers. Allows you to edit a specific classifier. |
To edit a classifier, click its name. |
Incoming Code Point (Alias) |
Displays CoS values and aliases to which forwarding class and loss priority are mapped. |
None. |
Classify to Forwarding Class |
Displays forwarding classes that are assigned to specific CoS values and aliases of a classifier. |
None. |
Classify to Loss Priority |
Displays loss priorities that are assigned to specific CoS values and aliases of a classifier. |
None. |
Add |
Opens a page that allows you to define classifiers. |
To add a classifier, click Add. |
Delete |
Deletes a specified classifier. |
To delete a classifier, locate the classifier, select the check box next to it, and click Delete. |
| Add a Classifier/Edit Classifier | ||
Classifier Name |
Specifies the name for a classifier. |
To name a classifier, type the name—for example, ba-classifier. |
Classifier Code Point Mapping |
Sets the forwarding classes and the packet loss priorities (PLPs) for specific CoS values and aliases. |
None. |
Incoming Code Point |
Specifies the CoS value in bits and the alias of a classifier for incoming packets. |
To specify a CoS value and alias, either select preconfigured ones from the list or type new ones. For information about forwarding classes and aliases assigned to well-known DSCPs, see Table 244. |
Forwarding Class |
Assigns the forwarding class to the specified CoS value and alias. |
To assign a forwarding class, select either one of following default forwarding classes or one that you have configured:
|
Loss Priority |
Assigns a loss priority to the specified CoS value and alias. |
To assign a loss priority, select one of the following:
|
Add |
Assigns a forwarding class and loss priority to the specified CoS value and alias. A classifier examines the incoming packet's header for the specified CoS value and alias and assigns it the forwarding class and loss priority that you have defined. |
To assign a forwarding class and loss priority to a specific CoS value and alias, click Add. |
Delete |
Removes the forwarding class and loss priority assignment from the classifier. |
To remove the forwarding class and loss priority assignment, select it and click Delete. |
Figure 101 shows the initial Quick Configuration page for defining rewrite rules, and Table 251 describes the related fields. Use the rewrite rules to alter the CoS values in outgoing packets to meet the requirements of the targeted peer. A rewrite rule examines the forwarding class and loss priority of a packet and sets its bits to a corresponding value specified in the rule.
Figure 101: Rewrite Rules Quick Configuration Page

Table 251: Rewrite Rules Quick Configuration Page Summary
Field |
Function |
Your Action |
|---|---|---|
| Rewrite Rules Summary | ||
DSCP |
Allows you to redefine DSCP IPv4 code point values of outgoing packets. |
To redefine a DSCP code point value, click DSCP. |
DSCP IPv6 |
Allows you to redefine DSCP IPv6 code point values. |
To redefine a DSCP IPv6 code point value, click DSCP IPv6. |
MPLS EXP |
Allows you to redefine MPLS experimental (EXP) bits. |
To redefine MPLS EXP bits, click MPLS EXP. |
IPv4 Precedence |
Allows you to redefine IPv4 precedence code point values. |
To redefine an IPv4 precedence code point value, click IPv4 Precedence. |
Rewrite Rule Name |
Displays names of defined rewrite rules. Allows you to edit a specific rule. |
To edit a rule, click its name. |
Forwarding Class |
Displays forwarding classes associated with a specific rewrite rule. |
None. |
Loss Priority |
Displays loss priority values associated with a specific rewrite rule, |
None. |
Rewrite Outgoing Code Point To |
Displays the CoS values and aliases that a specific rewrite rule has set for a specific forwarding class and loss priority. |
None. |
Add |
Opens a page that allows you to define a new rewrite rule. |
To add a rewrite rule, click Add. |
Delete |
Removes specified rewrite rules. |
To remove a rule, select the check box next to it and click Delete. |
| Add a Rewrite Rule/Edit Rewrite Rule | ||
Rewrite Rule Name |
Specifies a rewrite rule name. |
To name a rule, type the name—for example, rewrite-dscps. |
Code Point Mapping |
Rewrites outgoing CoS values of a packet, based on the forwarding class and loss priority. Allows you to remove a Code Point Mapping entry. |
To configure the CoS value assignment, follow these steps:
To remove a code point mapping entry, select it and click Delete. |
Figure 102 shows the initial Quick Configuration page for defining schedulers, scheduler maps, and random early detection (RED) drop profiles. Using schedulers, you can assign attributes to queues and thereby provide congestion control to a particular class of traffic. These attributes include the amount of interface bandwidth, memory buffer size, transmit rate, RED drop profiles and priority.
To configure schedulers using the Quick Configuration pages:
Figure 102: Schedulers Quick Configuration Page

Table 252: RED Drop Profiles Quick Configuration Page Summary
Table 253: Schedulers Quick Configuration Page Summary
Table 254: Scheduler Maps Quick Configuration Page Summary
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Note: SRX 3400, SRX 3600, SRX 5600, and SRX 5800 devices do not support Virtual Channels. |
Figure 103 shows the initial Quick Configuration page for defining virtual channel groups, and Table 255 describes the related fields. Use virtual channels to avoid oversubscription of links by limiting traffic from a higher aggregated bandwidth to a lower one—for example, to limit traffic from a main office to branch offices. You channelize this traffic by applying queuing, packet scheduling, and accounting rules to logical interfaces.
Figure 103: Virtual Channel Group Quick Configuration Page

Table 255: Virtual Channel Group Quick Configuration Page Summary
Field |
Function |
Your Action |
|---|---|---|
| Virtual Channel Groups Summary | ||
Virtual Channel Group Name |
Displays names of defined virtual channel groups. Allows you to edit a virtual channel group. |
To edit a virtual channel group, click its name. |
Virtual Channel Name |
Displays names of defined virtual channels. Allows you to edit a virtual channel. |
To edit a virtual channel, click its name. |
Default |
Marks the default virtual channel of a group. One of the virtual channels in a group must be configured as the default channel. Any traffic not explicitly directed to a particular channel is transmitted by this channel. |
None. |
Scheduler Map |
Displays the scheduler map assigned to a particular virtual channel. |
None. |
Shaping Rate |
Displays the shaping rate configured for a virtual channel. |
None. |
Add |
Opens a page that allows you to add a virtual channel group. |
To add a virtual channel group, click Add. |
Delete |
Removes a specific virtual channel group. |
To remove a specific virtual channel group, locate its name, select the check box next to it, and click Delete. |
| Add a Virtual Channel Group/Edit a Virtual Channel Group | ||
Virtual Channel Group Name |
Specifies a name for a virtual channel group. |
To name a group, type the name—for example, wan-vc-group. |
Add |
Creates a virtual channel group. Opens a page that allows you to add a virtual channel to the specified group. |
To create a virtual channel group, click Add. |
| Add a Virtual Channel/Edit Virtual Channel | ||
Virtual Channel Name |
Specifies the name of a virtual channel to be assigned to a virtual channel group. |
To name a virtual channel, either select a predefined name from the list or type a new name—for example, branch1–vc. |
Scheduler Map |
Specifies a predefined scheduler map to assign to a virtual channel. Scheduler maps associate schedulers with forwarding classes. For information about how to define scheduler maps, see Table 254. |
To specify a scheduler map, select it from the Scheduler Map list. |
Shaping Rate |
Specifies the shaping rate for a virtual channel. The shaper limits the maximum bandwidth transmitted by a virtual channel. Configuring a shaping rate is optional. If no shaping rate is configured, a virtual channel without a shaper can use the full logical interface bandwidth. |
To specify a shaping rate, select one of the following options:
|
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Note: SRX-series devices do not support WAN interfaces (including T1/E1 and channelized T1/E1. |
After you have defined CoS components, you must assign them to logical or physical interfaces. The CoS Quick Configuration pages allow you to assign scheduler maps to physical or logical interfaces and to assign forwarding classes, classifiers, rewrite rules, or virtual channel groups to logical interfaces.
Figure 104 shows the initial Quick Configuration page for assigning CoS components to interfaces. The page displays the interfaces available for CoS component assignment and the status of existing CoS components.
Figure 104: Assignment of CoS Components to Interfaces Quick Configuration Page

To assign CoS components to interfaces with Quick Configuration:
Table 256: Assigning CoS Components to Interfaces Quick Configuration Summary
Field |
Function |
Your Action |
|---|---|---|
| Class of Service Interfaces | ||
Interface Name (See the interface naming conventions in Network Interface Naming.) |
Lists the names of physical and logical interfaces configured on the system. Allows you to edit CoS component assignments to physical and logical interfaces. |
To edit an interface's CoS assignments, click the interface. |
Class of Service Overview |
Displays the CoS components assigned to a particular interface—for example, information about DSCP classifiers, EXP classifiers, or DSCP rewrite rules. |
None. |
Add |
Allows you to add a CoS service to a physical interface. |
To add a CoS service to a physical interface, click Add. |
Delete |
Removes CoS services assigned to a specific interface. |
To remove CoS services assigned to a specific interface, locate the interface name, click the check box next to it, and click Delete. |
| Add CoS Service to a Physical Interface/Edit CoS Physical Interface | ||
Physical Interface Name |
Specifies the name of a physical interface. Allows you to assign CoS components to a set of interfaces at the same time. |
To specify an interface for CoS assignment, type its name in the Physical Interface Name box. To specify a set of interfaces for CoS assignment, use the wildcard character (*)—for example, ge-0/*/0. |
Scheduler Map |
Specifies a predefined scheduler map for the physical interface. A scheduler map enables the physical interface to have more than one set of output queues. Note: For 4-port Fast Ethernet ePIMs, if you apply a CoS scheduler map on outgoing (egress) traffic, the device does not divide the bandwidth appropriately among the CoS queues. As a workaround, configure enforced CoS shaping on the ports. |
To specify a map for an interface, select it from the Scheduler Map list. |
Add |
Allows you to add a CoS service to a logical interface on a specified physical interface. |
To add a CoS Service to a logical interface, click Add. |
| Add CoS Service to a Logical Interface Unit/Edit CoS Logical Interface Unit | ||
Logical Interface Unit Name |
Specifies the name of a logical interface. Allows you to assign CoS components to all logical interfaces configured on a physical interface at the same time. |
To specify an interface for CoS assignment, type its name in the Logical Interface Unit Name box. To assign CoS services to all logical interfaces configured on this physical interface, type the wildcard character (*). |
Scheduler Map |
Specifies a predefined scheduler map for this interface. Note: You can configure either a scheduler map or a virtual channel group on a logical interface, not both. |
To assign a scheduler map to the interface, select it from the list. |
Forwarding Class |
Assigns a predefined forwarding class to incoming packets on a logical interface. |
To assign a forwarding class to the interface, select it. |
Virtual Channel Group |
Applies a virtual channel group to a logical interface. Applying a virtual channel group creates a set of eight queues for each virtual channel in the group. Note: You can configure either a scheduler map or a virtual channel group on a logical interface, not both. |
To specify a virtual channel group for the interface, select it from the list. |
Classifiers |
Allows you to apply classification maps to a logical interface. Classifiers assign a forwarding class and loss priority to an incoming packet based on its CoS value. |
To assign a classification map to the interface, select an appropriate classifier for each CoS value type used on the interface. |
Rewrite Rules |
Allows you to apply rewrite rule configurations to a logical interface. Rewrite rules rewrite the CoS values in an outgoing packet based on forwarding class and loss priority. You can choose to apply your own rewrite rule or a default one. The default rewrite assignments are based on the default bit definitions of DSCP, DSCP IPv6, MPLS EXP, and IP precedence. |
To apply a rewrite rule configuration to the interface, select a rule for each CoS value type used on the interface. |