FW: RRQ Registration in H.323 V2

Chris Purvis Chris.Purvis at MADGE.COM
Fri Apr 23 06:23:18 EDT 1999


Rob,

What I'm struggling for here is to understand what this common alias
("something like voip-gw.hotmail.com") is used for, and why you have it at
all.  Until I understand that I can not suggest how you solve your problem.

As for the issue of multiple aliases in RRQ, please find enclosed my musings
on the subject, sent to the IMTC h323implementer's reflector just two days
ago!

Regards,
Chris


> -----Original Message-----
> From: Rob B [mailto:robb112 at HOTMAIL.COM]
> Sent: 23 April 1999 2:46
> To: ITU-SG16 at MAILBAG.INTEL.COM
> Subject: Re: FW: RRQ Registration in H.323 V2
>
>
> Chris,
>
> H.323 V2 specifically says that each alias address should
> map to a unique transport address. So, as you pointed out
> my second RRQ would get rejected because alias is the
> same "voip-gw.hotmail.com" but a different transport
> address is registered :-(
>
> So, the only option left for me is to choose some dummy
> alias in my RRQs.
>
> Section 7.2.2 H.323V2
> "A Gateway or MCU may register a single Transport address or
> multiple transport addresses. The use of multiple transport
> addresses may simplify the routing of calls to specific ports"
>
> How can a _single_ gateway achieve the above stated. (Because
> what I am doing by sending multiple RRQs with different aliases
> is essentially simulating multiple logical gateways in the network.)
>
> Btw, one another related question. What is the meaning of
> multiple callSignalAddresses of _same_ transport type in
> RRQ.callSignalAddress. Is this possible and if possible how will
> the gatekeeper use them? I have a private mail from one vendor that
> multiple callSignalAddresses of the same transport type are
> possible in RRQ but no one uses them. I think I have to
> agree with him.
>
> Thanks for your time.
> -Chris.
>
>
> >From this description it seems fairly clear that you (logically,
> from a
> >protocol point of view) have two gateways that happen to be
> collocated.  The
> >only alias you're passing around is the phone number, and that wants
> to go
> >to different places according to how it starts.  However in an
> earlier mail
> >you said you only had a single gateway because you only have a single
> >terminalAlias ("something like voip-gw.hotmail.com").  As this alias
> appears
> >not to be passed around at any point during call setup it appears
> >irrelevant, although registering the same alias to different
> (logical)
> >gateways to the same gatekeeper at the same time may cause problems
> to some
> >gatekeepers.
> >
> >Regards,
> >Chris
> >
> >> -----Original Message-----
> >> From: Rob B [mailto:robb112 at HOTMAIL.COM]
> >> Sent: 21 April 1999 7:10
> >> To: ITU-SG16 at MAILBAG.INTEL.COM
> >> Subject: Re: FW: RRQ Registration in H.323 V2
> >>
> >>
> >> Chris,
> >>
> >> >
> >> >Just trying to understand the problem fully before jumping in with
> a
> >> >suggested solution:
> >> >How are you expecting people to call via this gateway?
> >> >Is the intention to place a call to multiple destionationInfos,
> >> specifying
> >> >first an alias that identifies the gateway, followed by a full
> phone
> >> number
> >> >starting 408 or 409?  If not, what is the intended action from an
> >> endpoint
> >> >attempting to call through this gateway?
> >> >
> >>
> >> My customers would have something like Netmeeting. They would
> >> make calls with an area code, say like 1-408-555-6666.
> >>
> >> Let us say I have GW1 and GK. GW1 supports area codes 408 and
> >> 409. It registers these two voice call prefixes (1408 and 1409)
> >> with GK along with port numbers 2000 and 3000. Any incoming
> >> calls on port 2000 are automatically assumed to be outgoing
> >> calls to area code 408 (so that GW1 need not again parse the
> >> calledPartyNumber in the incoming message). Parsing of the
> >> remaining number would be done at much later point in time.
> >>
> >> Now, when a call originates from netmeeting, the ARQ would contain
> >> the destination telephone number (1408555666) in the
> >> "destinationInfo". GK receives this ARQ and figures out
> >> that it has GW1 which registered the prefix 1408. So, GK returns
> >> the <GW1 IP Address + 2000> to netmeeting. And netmeeting would
> >> directly send the Q.931 SETUP message GW1's port 2000.
> >>
> >> This is what I am looking for.
> >>
> >> Thanks,
> >> -Chris (R)
> >>
> >>
> >> >> >I have a question on RRQ registration in H.323V2. Let us say
> >> >> >I have a gateway that supports area codes 408, 409. I want
> >> >> >my gatekeeper to route calls to area codes 408 and 409
> >> >> >to my local TCP ports 2000 and 3000 respectively. How should
> >> >> >I construct my RRQ message?
> >> >> >
> >> >> >Shall I send two RRQs with same endpoint identifier
> >> >> >(because I have only one gateway) with tuples
> >> >> ><408, 2000> and <409, 3000>.
> >> >> >
> >> >> ><x,y> means:  x: carried in SupportedProtocols.prefix
> >> >> >              y: carried in callSignallingAddress of RRQ
> message
> >> >> >
> >> >> >Is my understanding correct?
> >> >> >
> >> >> >-Chris Rob
> >> >> >
> >> >> >
> >>
> >>
> >> _______________________________________________________________
> >> Get Free Email and Do More On The Web. Visit http://www.msn.com
> >>
>
>
> _______________________________________________________________
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>


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