neededFeaturesNotSupported Reject Reason for RAS missing in H225.0v4

Pete Cordell pete at TECH-KNOW-WARE.COM
Fri Dec 8 04:52:18 EST 2000

Sorry Paul, suffering from executive fever!!!  (Only reading the first

> On a side note, you say that an xRJ may be sent if "the GK does not
> those features or cannot find a EP that supports these neededFeatures".  I
> have a question about the latter: was it the intent that the GK would look
> for a registered endpoint that contains the needed features?  I'm not
> disputing the statement, but I don't believe that's clear in H.323.

By default I would only expect a GK to consider the entity identified in the
request and the entity would either support the features or not.  However,
in some cases endpoints may be reachable through multiple intermediate
devices such as gateways to SS7, ISDN, DPNSS or QSIG etc.  In that case the
needed features may be involved in selecting the forwarding path.

> Also,
> are the neededFeatures in an ARQ supposed to be propagated via an LRQ when
> LRQs are used to resolve addresses?

Yes.  I had assumed that that was 'standard' procedure in turning an ARQ
into a LRQ.  However, it does make sense to explicitly say it.  Note that in
the case of multicast LRQ, this is a case where EP selection may be based on
neededFeatures etc.


Pete Cordell
pete at
+44 1473 635863

For help on this mail list, send "HELP ITU-SG16" in a message to
listserv at

More information about the sg16-avd mailing list