outbound ring tone
ianobi:
@ drgeoff
Attached is a Wireshark trace of a call I have just made from my OBi1032 using sipgate to my mobile. I did not answer the call. Times show:
1643:17 - RTP established in both directions (early media).
I now hear ring back tone from PSTN / cellular.
1643:32 - CANCEL - when I hung up from the OBi1032.
In this situation the sipgate servers have no way of knowing for sure what the POTS/PSTN/cellular end point will return in way of audio. It might be a ring back tone, busy tone, announcements ("this number does not exist" etc), IVR announcements and so on. In this situation the voip provider needs to feed back the audio from the callee equipment to the caller before the call is answered or not by the called party. Actual speech cannot take place until the "200 OK" message is passed from sipgate back to the OBi. This will be done if the sipgate server detects a definite answer signal from the callee equipment, in this example that never happens.
This is a case where the "183 Session Progress" message from sipgate to the OBi contains all the information that the OBi needs to establish the RTP link. Sipgate received the equivalent information from the OBi in the original "INVITE" message.
One good reason for using early media in this way is to ensure that users are not charged for a call where they simply receive busy tone or some announcement.
drgeoff:
@ianobi
Thanks for that.
I've had a look at https://tools.ietf.org/html/rfc3960. One needs to be in the "really determined" category to enjoy reading such RFCs. :)
ianobi:
@drgeoff
Quote
I've had a look at https://tools.ietf.org/html/rfc3960. One needs to be in the "really determined" category to enjoy reading such RFCs.
Very true. My example was a simple one. If you add in call forking, calls being routed via many SIP hops, but the RTP being direct etc, etc ... just now I'm more interested in the cricket :D
ianobi:
Let's not forget the OP in all this discussion about "early media".
The GV situation is well described here by SteveInWA:
http://www.obitalk.com/forum/index.php?topic=9269.msg61383#msg61383
azrobert's test in Reply #8 proves that the ring back tone is being provided locally by the OBi. The OP needs to have a look in the relevant Tone Profile. There is a setting for Ringback Tone, which I would think would be the one used for any outgoing GV calls.
SteveInWA:
Ian, great job diving into early media, and thanks for linking to my posts.
I do have to chuckle, though, about how many times somebody comes to this forum with some really unusual configuration to accomplish some goal, determined to do it his way, even if there's a better, simpler, more technically-elegant solution. Then, a lengthy discussion ensues as to how to make the poster's weird setup work, rather than how to accomplish the overall goal in a better way. The best recent example of this was the guy who wanted to turn a decommissioned cell phone into a secret recording device, via his OBi.
We already went down this "forward inbound calls to my OB'i and out again to my cell phone" route with another poster.
If it were up to me, I'd control the call routing from the Google Voice user interface, which is designed precisely for this purpose, instead of routing calls inside the OBi. Removing some of that complexity and restoring defaults as appropriate, would probably fix this issue.
Aside from that, there's the "flow chart":
Is the beep really hurting your ears?
Is it preventing you from determining if the call is ringing or not?
Did you mess with the ring tone settings and create this issue yourself?
If no to all questions, fuggedaboudit.
Navigation
[0] Message Index
[#] Next page
[*] Previous page