In this section:


Use this feature to define multi-level Call Admission Control (CAC) policy using IP hierarchal trunks. A hierarchy is created by linking trunks together in a pyramid-type structure. Regular IP trunks are at the base of the pyramid; above them in the pyramid are IP linked trunks or shared CAC-limits pools.

A shared CAC-limits pool is a global resource that constrains the resource usage of a set of trunks. Both the limit and current usage is maintained for each value. A shared CAC-limits pool is not tied to a specific zone or address context. There may be up to 2,000 shared CAC limits pools on SBC.

Validation rules:

  • There can only be one parent for any object.
  • An IP trunk group can be assigned as child to any CAC-limits pool (parent).
  • A CAC-limits pool can be assigned as a parent to any other CAC-limits pool that does not have a parent of its own.
  • A CAC-limits pool cannot be assigned to a parent if it already has a CAC-limits pool child.
  • The children of a particular CAC-limits pool can be either CAC-limits pools or IP trunks.

Call processing rules when using shared CAC-limits pool involve:

  • Applying the configured limits.
  • Checking the limits of the parent above in the pyramid. If limits are met by all parents, the call is admitted.

The hierarchy has a maximum of three levels: two levels of shared CAC-limits pool and an IP trunk at the bottom. The hierarchy is built bottom up by assigning a parent to an existing trunk group or CAC-limits pool. The parents must exist before being assigned.

When deleting a parent and associated child CAC, be sure to first de-associate the child from the parent before deleting the parent CAC. Do not attempt to delete both in the same transaction. See examples below:


Deletion Scenario 1:

% delete addressContext AC1 zone ZONE_IAD sipTrunkGroup TG1 parentSharedCacLimitsPoolName 
% commit 
% delete global cac sharedCacLimitsPool CAC0 
% commit

Deletion Scenario 2:

% delete global cac sharedCacLimitsPool CAC0 parentSharedCacLimitsPoolName 
% commit 
% delete global cac sharedCAcLimitsPool CAC1 
% commit

Note

Unless annotated otherwise, the parameter values in this section apply to the SBC Core.


Note

SIP subscription CAC limits are not applied to SUBSCRIBE requests from registered users in access deployments.


Command Syntax

Use the following CLI syntax to configure global CAC policy:

% set global cac sharedCacLimitsPool <pool_name>
	bandwidthLimit <0-2000000000, unlimited>
	bandwidthLimitThreshold <0-100>
    bandwidthVideoThreshold <0-100>
	callLimit <0-2000000000, unlimited>
	callLimitThreshold <0-100>
	egress
		callBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		callRateMax <1-1000, unlimited> (SBC 7000 range is 1-3000, unlimited)
		otherReqBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		otherReqRateMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		registerBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		registerRateMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		subscriberBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		subscriberRateMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
	emergencyOversubscription <1-1000>
	ingress 
		callBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		callRateMax <1-1000, unlimited> (SBC 7000 range is 1-3000, unlimited)
		otherReqBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		otherReqRateMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		registerBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		registerRateMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		subscriberBurstMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
		subscriberRateMax <1-2000, unlimited> (SBC 7000 range is 1-6000, unlimited)
	parentSharedCacLimitsPoolName <name>
	registrationLimit <0-2000000000, unlimited>
	subscriptionLimit  <0-2000000000, unlimited>

Command Parameters

Global CAC Parameters

Global CAC Parameters

Parameter

Description

cac

Use this object to specify shared CAC-limits pool name.

sharedCacLimitsPool

  • <pool_name> – The name of the shared CAC-limits pool. Object containing CAC-limits that apply to a set of trunk groups.
  • bandwidthLimit – (Default is 'unlimited') Total Media Bandwidth Limit (in Kbits/sec). (range: 0-2000000000, or unlimited)
  • bandwidthLimitThreshold – (Default = 0) Enter threshold value (as a percentage) to specify bandwidth utilization notification threshold. (range: 0-100)
  • bandwidthVideoThreshold – (Default = 0) Enter threshold value (as a percentage of video bandwidth) to limit video streams to a specific bandwidth to prevent video calls consuming call bandwidth otherwise needed for audio calls. (range: 0-100)
  • callLimit – (Default is 'unlimited') The total number of concurrent calls (either ingress or egress) allowed. (range: 0-2000000000, or unlimited)
  • callLimitThreshold – (Default = 0) Call Limit utilization notification threshold, as a percentage. (range: 0-100)
  • egress – Egress-specific CAC configuration. (See Egress/Ingress Parameters table below for details)
  • emergencyOversubscription – (Default = 100) The percentage over the configured allowed number of resources for an IP trunk group that Emergency calls can consume. Up to 10x can be allocated. (range: 1-1000)
  • ingress – Ingress-specific CAC configuration. (See Egress/Ingress Parameters table below for details)
  • parentSharedCacLimitsPoolName – Name of an existing shared CAC-limits pool.
  • registrationLimit – (Default is 'unlimited') The total number of concurrent SIP registrations allowed. (range: 0-2000000000, or unlimited)
  • subscriptionLimit – (Default is 'unlimited') The total number of concurrent SIP subscriptions allowed. (range: 0-2000000000, or unlimited)

Egress/Ingress Parameters

The default value for all of the CAC parameters below is 'unlimited'.


Egress/Ingress Parameters

ParameterLength/RangeDescriptions
callBurstMax

SBC 5xx0/SWe: 1-2000, or unlimited

SBC 7000: 1-6000, or unlimited

<value> – Maximum allowed burst (above the allowed sustained rate) for egress call attempts.
callRateMax

SBC 5xx0/SWe: 1-1000, or unlimited

SBC 7000: 1-3000, or unlimited

<value> – Maximum sustained egress call rate allowed in calls/second.

NOTE: You can set both "callRateMax" and "callBurstMax" as "unlimited"; however, if you assign a value to one parameter, the other must also be assigned a value.

otherReqBurstMax

SBC 5xx0/SWe: 1-2000, or unlimited

SBC 7000: 1-6000, or unlimited)

<value>  Maximum allowed burst (above the allowed sustained rate) for all other egress out-of-dialog SIP request.
otherReqRateMax

SBC 5xx0/SWe: 1-2000, or unlimited

SBC 7000: 1-6000, or unlimited)

<value>Maximum sustained egress rate of all other out-of-dialog SIP request allowed in one second.

registerBurstMax

SBC 5xx0/SWe: 1-2000, or unlimited

SBC 7000: 1-6000, or unlimited)

<value> Maximum allowed burst (above the allowed sustained rate) for egress initial SIP registrations.

registerRateMax

SBC 5xx0/SWe: 1-2000, or unlimited

SBC 7000: 1-6000, or unlimited)

<value> Maximum sustained egress rate of initial SIP registrations allowed.

NOTE: You can set both "registerBurstMax" and "registerRateMax" as unlimited; however, if you assign a value to one parameter, the other must also have a value.

subscribeBurstMax

SBC 5xx0/SWe: 1-2000, or unlimited

SBC 7000: 1-6000, or unlimited)

<value>  Maximum allowed burst (above the allowed sustained rate) for egress initial SIP Subscribe request.

subscribeRateMax

SBC 5xx0/SWe: 1-2000, or unlimited

SBC 7000: 1-6000, or unlimited)

<value>  Maximum sustained egress rate of initial SIP SUBSCRIBE request allowed in subscribes/second.

 


Command Example

% set global cac sharedCacLimitsPool POOL bandwidthLimit 
   1000 bandwidthLimitThreshold 1 callLimit 1000 
   callLimitThreshold 1 egress callBurstMax 50
% show global cac
   sharedCacLimitsPool POOL {
	callLimit 1000;
	callLimitThreshold 1;
	bandwidthLimit 1000;
	bandwidthLimitThreshold 1;
	egress {
		callBurstMax 50;
	}
   }



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