To achieve efficient device failover to a backup/secondary Application Server, the SBC uses ARS to determine if a server is reachable, providing the ability to temporarily "blacklist" a server IP address when specified criteria are met. The ARS profile defines when to blacklist a peer and the recovery algorithm that defines when to remove blacklisting, restoring the peer into service. An ARS profile can be assigned to the services section of a SIP trunk group to trigger the blacklisting and recovery of any SIP peer(s) associated with the trunk group. Refer to Address Reachability Service for more information on using ARS and ARS profiles.
Ribbon recommends to not configure Path Check Profile and SIP ARS Profile on the same peer to avoid unexpected results. As a general rule, the Path Check Profile is configured on the access leg where there is less traffic, and the ARS Profile is configured on the peer leg where there is continuous traffic.
Command Syntax
% set profiles services sipArsProfile <profile name> blkListAlgNoRetryAfterDuration <1-3600> blkListAlgNoRetryAfterNum503 <1-3600> blkListAlgRetryAfterMethods BIT 0 - sip-invite BIT 1 - sip-register BIT 2 - sip-subscribe BIT 3 - sip-notify BIT 4 - sip-options BIT 5 - sip-message BIT 6 - sip-publish BIT 7 - sip-info BIT 8 - sip-refer blkListAlgRetryAfterType sip-503 blkListAlgTimeoutsDuration <1-3600> blkListAlgTimeoutsNumTimeouts <1-3600> blkListAlgTimeoutsType sip-invite blkListAlgorithms <retryafter | timeouts | noRetryAfer> failureResponseCodes <400-699 | all |all4xx | all5xx | all6xx> midDialogArsScreenLevel <always | never | onlyIfNotBlackListDueto503> recoveryAlgForNoRetryAfter <probe|timer|none> recoveryAlgForTimeouts <probe|timer|none> recoveryAlgProbeDuration <1-3600> recoveryAlgProbeInterval <1-600> recoveryAlgProbeMethod sip-options recoveryAlgProbeNumResponses <1-32> recoveryAlgTimerDuration <1-3600> recoveryAlgorithm <probe|timer>
Command Parameters
The SIP ARS Profile Parameters are as shown:
SIP ARS Profile Parameters
Parameter | Length/Range | Description |
---|---|---|
| 1-23 |
|
| N/A | Identifies blacklisting algorithm to use for the ARS Profile. Any combination of triggers can be specified for a profile.
|
| 1 - 3600 | The number of SIP 503 responses without a Retry After header events sent by a peer to trigger blacklisting of that peer endpoint. The default is 1. |
| 1 - 3600 | The duration, in seconds, in which the SIP 503 responses without a Retry After header events must occur to trigger blacklisting of the peer sending the responses. The default is 1. |
| N/A | Use to specify the SIP status code type which includes a 'Retry-After' value (currently, the only supported value is
|
| 1-3600 | Duration (in seconds) in which the specified number of timeouts must occur. (default = 1). |
| 1-3600 | The number of timeout events for a single INVITE transaction (including any retransmissions) before black listing the address. (default = 1). |
| N/A | The timeout trigger type (currently, only
|
failureResponseCodes | 400-699, or | Use this parameter to define one or more response codes to treat as failure responses. The options include the following:
INFO: When you use more than one value, enclose the values in square brackets [ ], separating each value with a space. Entering a value without using brackets appends the value to the existing configuration. NOTE: Ensure |
midDialogArsScreenLevel | N/A | Use this parameter to control when to apply ARS to a mid-dialog request.
|
| 1-3600 | Duration (in seconds) in which the specified number of responses must occur. (default = 1). |
| 1-600 | The probe interval value, in seconds. (default = 1). |
| N/A | Specifies the probe method (currently, only
|
| 1-32 | The number of consecutive responses to occur before removing an entry from the black list. (default = 1). |
| 1-3600 | Duration (in seconds) that the IP address remains blacklisted. (default = 1). |
| N/A | The recovery algorithm to use once the peer is blacklisted.
|
blkListAlgRetryAfterMethods | Use this parameter to specify the SIP request types to retry after blacklist algorithm. The options include:
| |
recoveryAlgForTimeouts | N/A | Specifies the type of recovery algorithm for the endpoints blacklisted with timeouts algorithm.
none , the SBC continues with the default behavior which is specified in the recoveryAlgorithm flag. |
recoveryAlgForNoRetryAfter | N/A | Specifies the type of recovery algorithm for the endpoints blacklisted with 503 noRetryAfter algorithm.
Note: When the flag is set to |
Command Examples
The following example configures a SIP ARS profile named "ARSPROFILE1" using the various objects and parameters.
% set profiles services sipArsProfile ARSPROFILE1 blkListAlgTimeoutsDuration 34 blkListAlgNoRetryAfterNum503 3200 blkListAlgRetryAfterMethods sip-invite blkListAlgRetryAfterType sip-503 blkListAlgTimeoutsDuration 1 blkListAlgorithms retryafter blkListAlgTimeoutsNumTimeouts 1 blkListAlgTimeoutsType sip-invite blkListAlgorithms retryafter failureResponseCodes all midDialogArsScreenLevel always recoveryAlgForNoRetryAfter none recoveryAlgForTimeouts timer recoveryAlgProbeDuration 20 recoveryAlgProbeInterval 15 recoveryAlgProbeMethod sipoptions recoveryAlgProbeNumResponses 2 recoveryAlgTimerDuration 123 recoveryAlgorithm probe
To configure a single failureResponseCodes
value for a SIP ARS Profile:
% set profiles services sipArsProfile ARSPROFILE1 failureResponseCodes 404
To set multiple failureResponseCodes
values:
% set profiles services sipArsProfile ARSPROFILE1 failureResponseCodes [404 503 all6xx]
To delete a single failureResponseCodes
value:
% delete profiles services sipArsProfile ARSPROFILE1 failureResponseCodes all6xx
To delete all failureResponseCodes
values:
% delete profiles services sipArsProfile ARSPROFILE1 failureResponseCodes []