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|    comp.protocols.tcp-ip    |    TCP and IP network protocols.    |    14,669 messages    |
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|    Message 13,734 of 14,669    |
|    John to All    |
|    Re: Wireshark question    |
|    22 Apr 11 22:18:38    |
      From: john@nospam.thanks              > I took a look at the file. No SIP there, but just rtp, g.711 ulaw. _lots_       > of jitter. Way beyond the requirements for a stable SIP call.              Yes, I deleted all other packets except RTP.              I installed a softphone on a stationary computer and made a call from that       phone       to a softphone on my Android cell phone. The Android phone received the       SIP call via WiFi on a different network. So that might explain the jitter       you saw?                     > Your observation is the standard jitter problem. When you play the stream       > in retrospect, all the packets are there, so wireshark can play out all       > the sound.              I don't agree. I think Wireshark is not capable of demultiplexing RTP packet       streams which is what the capture shows...The RTP stream is a stream of       multiplexed       RTP packets...some with payload type 101 and others with payload type 0.       Anyway...The payload type 101 packets shouldn't be there as they are       "out-of-band" DTMF tones...You don't signal DTMF tones _and_ send RTP       packets on top of that...that doesn't make any sense in my head. Either you       signal DTMF tones or you send the actual DTMF audio in RTP packets.              > But when the actual telephones did the call, you had a window of somewhere       > between 18 and 42 milliseconds for the packets to get there. Depending       > on the actual SIP implementation. (Or, RTP audio side). And a significant       > part of these packets got there, but too late to be useful.              That's a whole other issue :o)              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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