Determining Source And Destination Url; Source Ip Group Classification - AudioCodes mediapack MP-500 User Manual

9.2.3.1

Determining Source and Destination URL

The SIP protocol has more than one URL in a dialog establishing request that might
represent the source and destination URL. When handling an incoming request, the device
determines which SIP headers are used for source and destination URL's. Once these
URL's are determined, the input user and host are taken from these URLs.
INVITE dialogs:
•
Source URL: if exists, obtained from the P-Asserted\Preferred-Identity header;
Otherwise, from the From header
•
Destination URL: obtained from the Request URI
REGISTER dialogs:
•
Source URL: obtained from the To header
•
Destination URL: obtained from the Request URI
9.2.3.2

Source IP Group Classification

The device now supports the configuration of rules for classifying incoming SIP dialog
initiating request. The classification identifies the incoming SIP dialog request as belonging
to a specific IP Group (from where the SIP dialog request originated).
Classification begins in the device's Registration database, where it searches for a match
by checking if the request arrived from a registered user:
Compares received Contact to the Contact of the registered user
Compares P-Asserted/From URL to the registered AOR
If the database search is unsuccessful, the classification process proceeds with locating a
Proxy Set (associated with the SIP dialog request's IP address) and then finding a match
with a corresponding IP Group in the IP Group table. Each IP Group can be classified
according to its Proxy Set (if in the IP Group table the parameter ClassifyByProxySet is
enabled). If enabled, the device classifies Requests arriving from the IP Group's Proxy Set
as coming from this IP Group. The classification is done according to the Proxy IP list (in
case of host names, then according to the dynamically resolved IP address list). Note that
this classification is not relevant in cases where multiple IP Groups use the same Proxy
Set.
If classification based on Proxy Set is unsuccessful, the device proceeds to the
Classification table, which searches for a source IP Group based on the following matching
rules: Source IP Address, Source Username Prefix, Source Host Prefix, Destination
Username Prefix, Destination Host Prefix, and Source SRD.
If the above classification process fails to determine the source IP Group to which the
incoming packet belongs, the call can either be rejected, or allowed and processed (by
assigning it to the default IP Group of the default SRD). This last classification is
determined by the parameter AllowUnclassifiedCalls.
This IP Group is afterwards used for the following purposes:
Input for the manipulation and routing processes
Defining SIP behavior and IP Profile, Media realm and matching account
Note:
SIP User's Manual
Incoming REGISTER messages are recorded in the device's database and
sent to a destination only if they are associated with a source IP Group that is
of USER type.
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MP-500 MSBG
Document #: LTRT-12801