Greetings,
Ringback capability is not dead. T1S1 are looking at this and it is reflected in the currect version of the T1.628 - 2000, Emergency Calling Service standard.
Regards
Gordon Kelly
Systems Engineer
CML Emergency Services
Ph. 819-778-2053 ext. 402
E-mail [EMAIL PROTECTED]
-----Original Message-----
From: Ovidiu Sas [mailto:[EMAIL PROTECTED]]
Sent: September 24, 2001 12:21 PM
To: amir gts
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: [911] Re: E911 call signals in SIP
Hi
I think that your picture looks like this:
(mgcp) (sip) (mgcp)
RGW CMS MGC TG
---hd---->
<---ACK---
--(re-Invite - hold)->
<---------ACK---------
--RQNT(SUS)-->
<---ACK-------
<----NTFY(orbk)
-----ACK------>
<--(????????)-------
-----ACK--------->
<-RQNT(wt)-
----ACK--->
I'm not familiar with mgcp but I assume that:
TG : Trunking Gateway
MGC: Media Gateway Controller
CMS: Call Management server/Call Agent
RGW: Residential Gateway
I didn't see any SIP work dealing with CAS signals or with 911.
But you don't care about CMS, you can bypass the SIP signaling using
RTP:
(mgcp) (sip) (mgcp)
RGW CMS MGC TG
---hd---->
<---ACK---
--(re-Invite - hold)->
<---------ACK---------
--RQNT(SUS)-->
<---ACK-------
<----NTFY(orbk)
-----ACK------>
<================ RTP (rfc2833)======================
The Ringback Operator signal will be reconstructed by the Residential
Gateway. If you care about CMS, I don't know if mgcp allows the RGW to
notify the CMS about the fact that orbk is _played_ and not_received_.
As I know, the Ringback Operator signal is used by 911 and NOT by
E911. The existing 911 implementation will be replaced soon by E911.
Ovidiu
________________
amir gts writes:
> Thanks Ovidiu,
> The SUS/RES signals can be passed the same way as
> 'draft-ietf-sip-isup-03.txt' shows,
> Thanks a lot for that,
> But I still have a problem how to pass all the other signals because this is
> not a matter of
> passing signals via RTP, I have to pass them via SIP,
> Here is an illustration of the flow architecture on the E911, this part of
> the flow
> is after connecting the call, the caller (RGW) hangs-up, which will cause
> sending a SUS
> to the TG, in this state, when the operator wishes to alert the caller, it
> issues a signal called
> 'orbk' - operator ringback (part of the CAS MO package rfc 3064), when this
> signal arrives to the MGC it has to notify
> the CMS via SIP about this signal so that the CMS can issue the RGW an
> alerting tone.
>
> (mgcp) (sip) (mgcp)
> RGW CMS MGC
> TG
> --hd------->
> <--ACK---
> -- (re-Invite - hold) ->
> <---ACK------------
> --RQN
> T(SUS)-->
>
> <---ACK--------
>
> <----NTFY(orbk)
> ----
> -ACK------>
> <--(????????)-------
> -----ACK--------->
> <--RQNT(wt)--
> -----ACK------>
>
> As you can see, I have to pass this signal via SIP , not via RTP because
> this signal have to get to the
> CMS (Call Management server/Call Agent) in order to issue the correct signal
> to the caller.
>
> Amir.
>
> ----- Original Message -----
> From: "Ovidiu Sas" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Cc: "amir gts" <[EMAIL PROTECTED]>
> Sent: Friday, September 21, 2001 5:51 PM
> Subject: [Sip-implementors] Re: E911 call signals in SIP
>
>
> >
> >
> > For CAS specific signals you can use rfc2833:
> > RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals
> >
> > For SUS/RES signals see draft-ietf-sip-isup-03.txt:
> > ISUP to SIP Mapping
> >
> > Ovidiu
> > ________________
> > amir gts writes:
> > > This is a multi-part message in MIME format.
> > >
> > > ------=_NextPart_000_0015_01C022E3.3B8CAED0
> > > Content-Type: text/plain;
> > > charset="iso-8859-1"
> > > Content-Transfer-Encoding: quoted-printable
> > >
> > > Hi All,
> > > I'm implementing SIP UA's in Call-Agents, and i am trying to find
> > > how to pass CAS specific signals like 'orbk' (operator ringback) or =
> > > 'sus' / 'res'
> > > through SIP, does anyone has an idea or maybe there is a draft that =
> > > explains
> > > that.
> > >
> > > Thanks in advance,
> > > Amir.
> > >
> >
> > _______________________________________________
> > Sip-implementors mailing list
> > [EMAIL PROTECTED]
> > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
> >
>
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