Ethereal-users: [Ethereal-users] Re: RTCP malformed frame

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From: Michael Oliveras <moliveras@xxxxxxxxxxxxx>
Date: Tue, 11 Jan 2005 22:48:41 -0500 (GMT-05:00)
I opened up the RTCP packet with ethereal 0.9.11 and the original h323 plugin, and it is able to decode the packet correctly.  It seems that the RTCP packet has a Sender report followed by a Source Descriptoin in the same packet, which seems to be the same issue another user had reported.   I included a decode of the RTCP packet with both versions of ethereal if anyone cares to take a look.

Regards,

Mike






-----Original Message-----
From: Michael Oliveras <moliveras@xxxxxxxxxxxxx>
Sent: Jan 8, 2005 11:39 AM
To: ethereal-users@xxxxxxxxxxxx
Subject: RTCP malformed frame

All of the RTCP frames from a particular vendor are decoded as ethereal as malformed.  Can someone take a look and see if there is a dissection bug?  I included a sample.

Thanks,

Mike



Frame 1 (126 bytes on wire, 126 bytes captured)
    Arrival Time: Jan  7, 2005 11:02:44.560240000
    Time delta from previous packet: 0.000000000 seconds
    Time relative to first packet: 0.000000000 seconds
    Frame Number: 1
    Packet Length: 126 bytes
    Capture Length: 126 bytes
Ethernet II, Src: 00:d0:ff:90:98:00, Dst: 00:07:e9:0c:91:52
    Destination: 00:07:e9:0c:91:52 (Intel_0c:91:52)
    Source: 00:d0:ff:90:98:00 (Cisco_90:98:00)
    Type: IP (0x0800)
Internet Protocol, Src Addr: 209.58.84.226 (209.58.84.226), Dst Addr: 209.58.84.42 (209.58.84.42)
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 112
    Identification: 0x7230
    Flags: 0x00
        .0.. = Don't fragment: Not set
        ..0. = More fragments: Not set
    Fragment offset: 0
    Time to live: 63
    Protocol: UDP (0x11)
    Header checksum: 0xbdcb (correct)
    Source: 209.58.84.226 (209.58.84.226)
    Destination: 209.58.84.42 (209.58.84.42)
User Datagram Protocol, Src Port: 7839 (7839), Dst Port: 60823 (60823)
    Source port: 7839 (7839)
    Destination port: 60823 (60823)
    Length: 92
    Checksum: 0x0000 (none)
Real-time Transport Control Protocol
    Version: RFC 1889 Version (2)
    Padding: False
    Reception report count: 1
    Packet type: Sender Report (200)
    Length: 12
    Sender SSRC: 0
    Timestamp, MSW: 3314101148
    Timestamp, LSW: 3256352768
    RTP timestamp: 11040
    Sender's packet count: 0
    Sender's octet count: 0
    Source 1
        Identifier: 234312949
        SSRC contents
            Fraction lost: 0 / 256
            Cumulative number of packets lost: 0
        Extended highest sequence number received: 18267
            Sequence number cycles count: 0
            Highest sequence number received: 18267
        Interarrival jitter: 11
        Last SR timestamp: 824463097
        Delay since last SR timestamp: 17039
Real-time Transport Control Protocol
    Version: RFC 1889 Version (2)
    Padding: False
    Source count: 1
    Packet type: Source description (202)
    Length: 7
    Chunk 1, SSRC/CSRC 0
        Identifier: 0
        SDES items
            Type: CNAME (user and domain) (1)
            Length: 19
            Text: e00a9@209.58.84.226

0000  00 07 e9 0c 91 52 00 d0 ff 90 98 00 08 00 45 00   .....R........E.
0010  00 70 72 30 00 00 3f 11 bd cb d1 3a 54 e2 d1 3a   .pr0..?....:T..:
0020  54 2a 1e 9f ed 97 00 5c 00 00 81 c8 00 0c 00 00   T*.....\........
0030  00 00 c5 89 2b 9c c2 18 00 00 00 00 2b 20 00 00   ....+.......+ ..
0040  00 00 00 00 00 00 0d f7 54 f5 00 00 00 00 00 00   ........T.......
0050  47 5b 00 00 00 0b 31 24 4e f9 00 00 42 8f 81 ca   G[....1$N...B...
0060  00 07 00 00 00 00 01 13 65 30 30 61 39 40 32 30   ........e00a9@20
0070  39 2e 35 38 2e 38 34 2e 32 32 36 00 00 00         9.58.84.226...

No.     Time        Source                Destination           Protocol Info
      1 0.000000    209.58.84.226         209.58.84.42          RTCP     Sender Report[Malformed Packet]

Frame 1 (126 bytes on wire, 126 bytes captured)
    Arrival Time: Jan  7, 2005 11:02:44.560240000
    Time delta from previous packet: 0.000000000 seconds
    Time since reference or first frame: 0.000000000 seconds
    Frame Number: 1
    Packet Length: 126 bytes
    Capture Length: 126 bytes
Ethernet II, Src: 00:d0:ff:90:98:00, Dst: 00:07:e9:0c:91:52
    Destination: 00:07:e9:0c:91:52 (Intel_0c:91:52)
    Source: 00:d0:ff:90:98:00 (Cisco_90:98:00)
    Type: IP (0x0800)
Internet Protocol, Src Addr: 209.58.84.226 (209.58.84.226), Dst Addr: 209.58.84.42 (209.58.84.42)
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 112
    Identification: 0x7230 (29232)
    Flags: 0x00
        0... = Reserved bit: Not set
        .0.. = Don't fragment: Not set
        ..0. = More fragments: Not set
    Fragment offset: 0
    Time to live: 63
    Protocol: UDP (0x11)
    Header checksum: 0xbdcb (correct)
    Source: 209.58.84.226 (209.58.84.226)
    Destination: 209.58.84.42 (209.58.84.42)
User Datagram Protocol, Src Port: 7839 (7839), Dst Port: 60823 (60823)
    Source port: 7839 (7839)
    Destination port: 60823 (60823)
    Length: 92
    Checksum: 0x0000 (none)
Real-time Transport Control Protocol
    10.. .... = Version: RFC 1889 Version (2)
    ..0. .... = Padding: False
    ...0 0001 = Reception report count: 1
    Packet type: Sender Report (200)
    Length: 12
    Sender SSRC: 0
    Timestamp, MSW: 3314101148
    Timestamp, LSW: 3256352768
    RTP timestamp: 11040
    Sender's packet count: 0
    Sender's octet count: 0
    Source 1
        Identifier: 234312949
        SSRC contents
            Fraction lost: 0 / 256
            Cumulative number of packets lost: 0
        Extended highest sequence number received: 18267
            Sequence number cycles count: 0
            Highest sequence number received: 18267
        Interarrival jitter: 11
        Last SR timestamp: 824463097
        Delay since last SR timestamp: 17039
Real-time Transport Control Protocol
    10.. .... = Version: RFC 1889 Version (2)
    ..0. .... = Padding: False
    ...0 0001 = Source count: 1
    Packet type: Source description (202)
    Length: 7
    Padding
    Chunk 1, SSRC/CSRC 18048304
        Identifier: 18048304
        SDES items
            Type: Unknown (48)
            Length: 97
[Malformed Packet: RTCP]

0000  00 07 e9 0c 91 52 00 d0 ff 90 98 00 08 00 45 00   .....R........E.
0010  00 70 72 30 00 00 3f 11 bd cb d1 3a 54 e2 d1 3a   .pr0..?....:T..:
0020  54 2a 1e 9f ed 97 00 5c 00 00 81 c8 00 0c 00 00   T*.....\........
0030  00 00 c5 89 2b 9c c2 18 00 00 00 00 2b 20 00 00   ....+.......+ ..
0040  00 00 00 00 00 00 0d f7 54 f5 00 00 00 00 00 00   ........T.......
0050  47 5b 00 00 00 0b 31 24 4e f9 00 00 42 8f 81 ca   G[....1$N...B...
0060  00 07 00 00 00 00 01 13 65 30 30 61 39 40 32 30   ........e00a9@20
0070  39 2e 35 38 2e 38 34 2e 32 32 36 00 00 00         9.58.84.226...