Adaptations

Last Updated : Oct 04, 2023 |
You can use Adaptations to modify SIP messages that are:
  • entering a Session Manager instance (ingress adaptation).
  • leaving a Session Manager instance (egress adaptation).
Session Manager supports the following adaptations:
  • Digit based adaptations
  • Device adaptations
  • Regular Expression adaptations
Session Manager Release 10.2 and later support the StirShakenAdapter adaptation module. The StirShakenAdapter operates on inbound and outbound call (INVITE) requests and can modify the STIR/SHAKEN information present in the SIP messaging. For more information about StirShakenAdapter, see Stir Shaken Adapter.
The adaptation function converts strings containing calling and called party numbers from the local dial plan of a SIP entity to the dial plan administered on the Session Manager, and vice-versa. Adaptation also supports special SIP protocol conventions for other SIP entities. Each administered SIP entity can have its own unique adaptation, or one adaptation can be shared among multiple entities.
You can implement adaptations as software modules that you create and deploy to fit the needs of the system.
Session Manager includes a module called DigitConversionAdapter, which can convert digit strings in various message headers as well as hostnames in the Request-URI and other headers. The module also contains adaptation modules which perform protocol conversions such as for AT&T, Verizon, and Cisco systems, as well as the digit conversion. These adapters allow for modification of URIs specified using unique name-value pairs for egress adaptation. For example, you can replace the host name in the Request-URI with an administered host name during egress adaptation. An adaptation administered using Routing specifies the module to use as well as the digit conversion that is to be performed on headers in the SIP messages. Different digit conversions can be specified for ingress and egress adaptation.
Device adaptations facilitates assignment of device module to Device Mappings to modify SIP messages based on a particular User Agent or origination number. Session Manager supports the following pre-defined device adaptations:
  • PolycomEndpointAdapter
  • CiscoEndpointAdapter
  • SeltaEndpointAdapter
All adaptation modules provided with Session Manager convert DTMF message bodies in an INFO message between the following formats:
  • application/vnd.nortelnetworks.digits
  • application/dtmf-relay
  • application/dtmf
DTMF message bodies are automatically converted to application/dtmf-relay on ingress unless the noidtmf parameter is specified. DTMF message bodies are converted on egress to the format specified in the dtmf parameter.
Additionally, digit conversion can be specified to modify only origination type headers, only destination type headers, or both. The origination/source type URIs are:
  • From: See #1 below.
  • P-Asserted-Identity
  • History-Info (calling portion)
The destination type URIs are:
  • Request-URI: See #3 below.
  • Contact in 3xx response: See #2 below..
  • To: See #1 and #3 below.
  • Message Account in NOTIFY/message-summary body.
  • Refer-To in REFER message: See #2 below.
  1. The From and To headers are only modified by adaptation if the fromto module parameter is present and has the value of true. See Adaptation Module Administration below.
  2. Adaptations are only applied to the Contact header in a 3xx response and the Refer-To header in a REFER message, if the host-part of the URI is either the IP address of the Session Manager or a domain for which the Session Manager is authoritative.
  3. In Session Manager, Request-URI and To headers are not adapted on ingress if the host part of the URI is an IP address that is different from the IP address of the Session Manager. If required, the new adaptation module parameter adaptForeignURI can be added to provide the earlier adaptation behavior prior to that of Session Manager 6.2 release.
  4. All adaptations strip the port and transport from the Request-URI if the host-part is adapted on egress. This behavior can be overridden with the keepPortTransport parameter.
Regular Expression Adaptations have zero or more ingress and/or egress ordered rules. Each Regular Expression Adaptation have up to two lists of one or more adaptations rules, one for ingress and the other for egress. You can define the order of the adaptation rules.