Hello Sip Implementors,
I am in need of an RTCP Guru. My SBC is sending out an RTCP Seder Report with "7" Source IPs and a frame size of 1088. Apparently they are claiming that this RTCP packet is causing their high density GW (Multiple TDM DS3's) to fail.
I have consulted with several subject matter experts - but you folks are the best!
I have three questions:
1. below is the pcap export of the RTCP packets they have been able to capture originating from our SBC. Is there anything unusual or out of RFC?
2. This issue is intermittent, which leads me to believe that the RTP Media is shuffled around quite a bit. I have not seen this occur in real time, as it is not easily reproducible. I’m pretty confident that our SBC does not generate arbitrary sources; so my theory is that the client side ep is sending us SIP signals that include these sources? Is this a reasonable assumption.
3. Last question – what field are the the Sources for RTCP generated by? Is it “via,” connection information?? (my apologies on this one – I should either know it or be able to find it)
Below are some txt based RTCP captures.
As always, Thanks in advance!!!
Best,
Albert
Frame 942 (1155 bytes on wire, 1155 bytes captured)
Ethernet II, Src: c8:4c:75:22:3d:a6 (c8:4c:75:22:3d:a6), Dst: HewlettP_e3:0c:d6 (00:1b:78:e3:0c:d6)
Internet Protocol, Src: 10.231.121.52 (10.231.121.52), Dst: 10.201.120.33 (10.201.120.33)
User Datagram Protocol, Src Port: 925 (925), Dst Port: 925 (925)
Source port: 925 (925)
Destination port: 925 (925)
Length: 1121
Checksum: 0x0000 (none)
Good Checksum: False
Bad Checksum: False
AUDIOCODES DEBUG RECORDING
Version: 0x02
Time Stamp: 05344AFAA3B1(5722154.378161 sec)
Source ID: 58
Dest ID: 58
Reserved: AA
Trace Point: Network -> Dsp (0)
Media Type: RTCP Packet (2)
Payload offset: 10
Header Extension
Packet source IP address: 10.101.1.9 (10.101.1.9)
Packet source UDP port: 22425
Packet destination UDP port: 18721
IP type of service: 0
Real-time Transport Control Protocol (Sender Report)
10.. .... = Version: RFC 1889 Version (2)
..1. .... = Padding: True
...0 0111 = Reception report count: 7
Packet type: Sender Report (200)
Length: 240 (964 bytes)
Sender SSRC: 0x33a6c201 (866566657)
Timestamp, MSW: 3506777311 (0xd1052cdf)
Timestamp, LSW: 2259152798 (0x86a7ef9e)
[MSW and LSW as NTP timestamp: Feb 15, 2011 16:48:31.5260 UTC]
RTP timestamp: 82492160
Sender's packet count: 331121
Sender's octet count: 10595872
Source 1
Identifier: 0x09bb552c (163271980)
SSRC contents
Fraction lost: 0 / 256
Cumulative number of packets lost: 26
Extended highest sequence number received: 46423
Sequence number cycles count: 0
Highest sequence number received: 46423
Interarrival jitter: 15
Last SR timestamp: 2535265796 (0x971d1604)
Delay since last SR timestamp: 181021966 (2762175 milliseconds)
Source 2
Identifier: 0x09c512b0 (163910320)
SSRC contents
Fraction lost: 0 / 256
Cumulative number of packets lost: 2
Extended highest sequence number received: 112
Sequence number cycles count: 0
Highest sequence number received: 112
Interarrival jitter: 23
Last SR timestamp: 0 (0x00000000)
Delay since last SR timestamp: 0 (0 milliseconds)
Source 3
Identifier: 0x0d2b4c6f (220941423)
SSRC contents
Fraction lost: 0 / 256
Cumulative number of packets lost: 30
Extended highest sequence number received: 48469
Sequence number cycles count: 0
Highest sequence number received: 48469
Interarrival jitter: 15
Last SR timestamp: 2138627571 (0x7f78ddf3)
Delay since last SR timestamp: 577654292 (8814304 milliseconds)
Source 4
Identifier: 0x0d517d3f (223444287)
SSRC contents
Fraction lost: 0 / 256
Cumulative number of packets lost: 53
Extended highest sequence number received: 43405
Sequence number cycles count: 0
Highest sequence number received: 43405
Interarrival jitter: 15
Last SR timestamp: 2267796733 (0x872bd4fd)
Delay since last SR timestamp: 448486637 (6843362 milliseconds)
Source 5
Identifier: 0x0e9391a4 (244552100)
SSRC contents
Fraction lost: 0 / 256
Cumulative number of packets lost: 0
Extended highest sequence number received: 311
Sequence number cycles count: 0
Highest sequence number received: 311
Interarrival jitter: 20
Last SR timestamp: 0 (0x00000000)
Delay since last SR timestamp: 0 (0 milliseconds)
Source 6
Identifier: 0x0fc09918 (264280344)
SSRC contents
Fraction lost: 0 / 256
Cumulative number of packets lost: 3
Extended highest sequence number received: 122
Sequence number cycles count: 0
Highest sequence number received: 122
Interarrival jitter: 15
Last SR timestamp: 0 (0x00000000)
Delay since last SR timestamp: 0 (0 milliseconds)
Source 7
Identifier: 0x132b8be4 (321620964)
SSRC contents
Fraction lost: 0 / 256
Cumulative number of packets lost: 0
Extended highest sequence number received: 310
Sequence number cycles count: 0
Highest sequence number received: 310
Interarrival jitter: 15
Last SR timestamp: 0 (0x00000000)
Delay since last SR timestamp: 0 (0 milliseconds)
Profile-specific extension: 140F67640000000300000074000000110000000000000000...
Real-time Transport Control Protocol (Source description)
10.. .... = Version: RFC 1889 Version (2)
..0. .... = Padding: False
...0 0001 = Source count: 1
Packet type: Source description (202)
Length: 30 (124 bytes)
Chunk 1, SSRC/CSRC 0x33A6C201
Identifier: 0x33a6c201 (866566657)
SDES items
Type: CNAME (user and domain) (1)
Length: 61
Text: ***@unique.zBDD1D716E31B4158.org
Type: PRIV (private extensions) (8)
Length: 49
Prefix length: 16
Prefix string: x-rtp-session-id
Text: 906F4F891777473EB1F8C7492BC5CBDE
Type: END (0)
[RTCP frame length check: OK - 1088 bytes]