Wireshark mailing list archives
Re: New Dissector only applied to first packet
From: Jan Willamowius <jan () willamowius de>
Date: Tue, 6 Nov 2012 21:53:25 +0100
Anders Broman wrote:
The use of multiplexing is negotiated in openLogicalChannel and openLogicalChannelAck. It can be bi-directional or only in one direction. If one side wants to _receive_ multiplexed RTP, it will add a multiplexedMediaChannel + control channel to the traversal parameters plus the payload type it expects. In the case of an H.460.19 client, those addresses must be disregarded again, because it may be behind a NAT and the real IPs will be determined by keepAlive packets.
[...]
Looking at the template that packet-h245.c is generated from, I don't really see where it says that the upcoming channel will be RTP. Is that implied and all upcoming channels are RTP right now ? Changing that to multiplexed-RTP is my priority right now.
[...]
It ought to be possible to set up the RTP or RTPmux data by using the information in TraversalParameters ::= SEQUENCE { multiplexedMediaChannel TransportAddress OPTIONAL, multiplexedMediaControlChannel TransportAddress OPTIONAL, multiplexID INTEGER(0..4294967295) OPTIONAL, keepAliveChannel TransportAddress OPTIONAL, keepAlivePayloadType INTEGER (0..127) OPTIONAL, keepAliveInterval TimeToLive OPTIONAL, ... } At least adding dissection of the parameter shouldn't be to difficult given an example trace.
I have captured a trace of a multiplexing call to test with. One capture contains one endpoint multiplexing to the H.323 gatekeeper and the other trace has the other endpoint in it too. http://www.gnugk.org/download/rtp-mux.pcap http://www.gnugk.org/download/rtp-mux-both.pcap Here is my dissector for H.460.19 rtp-mux (which right now can only be used for Decode As if the openLogicalChannel and openlogicalChannelAck packets are marked Ignore). http://www.gnugk.org/download/packet-h46019rtpmux.c Anders, how could one specify a different dissector for the upcoming channel in packet-h245.c ? Regards, Jan -- Jan Willamowius, jan () willamowius de, http://www.gnugk.org/ ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
Current thread:
- New Dissector only applied to first packet Jan Willamowius (Nov 02)
- Re: New Dissector only applied to first packet Guy Harris (Nov 02)
- Re: New Dissector only applied to first packet Jan Willamowius (Nov 02)
- Re: New Dissector only applied to first packet Guy Harris (Nov 02)
- Re: New Dissector only applied to first packet Jan Willamowius (Nov 02)
- Re: New Dissector only applied to first packet Guy Harris (Nov 04)
- Re: New Dissector only applied to first packet Jan Willamowius (Nov 05)
- Re: New Dissector only applied to first packet Anders Broman (Nov 06)
- Re: New Dissector only applied to first packet Jan Willamowius (Nov 06)
- Re: New Dissector only applied to first packet Anders Broman (Nov 07)
- Re: New Dissector only applied to first packet Jan Willamowius (Nov 02)
- Re: New Dissector only applied to first packet Guy Harris (Nov 02)