Hi

 

Pls. help us in resolving the problem that the SIP proxy server changes the Source and Destination port while replying for message. Pls. find the below message for the Reference In below message A cisco ata device (which is behind NAT with IP 192.168.10.52) is trying to register it self with SIP proxy server IP 172.16.101.10 with SRC port 5060 and DST port 5060, but when SIP proxy server replies back to the message the port number gets changed i.e SRC port 53492 and DST port 5060. Is there any way by which we can fix this port num.

 

No.     Time        Source                Destination           Protocol Info
532 152.672945  172.16.101.251        172.16.101.10         SIP      Request: REGISTER sip:172.16.101.10
 
 Frame 532 (469 bytes on wire, 469 bytes captured)
    Arrival Time: Nov  3, 2005 11:32:02.280623000
    Time delta from previous packet: 0.007492000 seconds
    Time since reference or first frame: 152.672945000 seconds
    Frame Number: 532
    Packet Length: 469 bytes
    Capture Length: 469 bytes
    Protocols in frame: eth:ip:udp:sip
Ethernet II, Src: Cisco_b5:15:f0 (00:04:c1:b5:15:f0), Dst: Dell_17:ea:82 (00:14:22:17:ea:82)
    Destination: Dell_17:ea:82 (00:14:22:17:ea:82)
    Source: Cisco_b5:15:f0 (00:04:c1:b5:15:f0)
    Type: IP (0x0800)
Internet Protocol, Src: 172.16.101.251 (172.16.101.251), Dst: 172.16.101.10 (172.16.101.10)
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x68 (DSCP 0x1a: Assured Forwarding 31; ECN: 0x00)
        0110 10.. = Differentiated Services Codepoint: Assured Forwarding 31 (0x1a)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 455
    Identification: 0x01f8 (504)
    Flags: 0x00
        0... = Reserved bit: Not set
        .0.. = Don't fragment: Not set
        ..0. = More fragments: Not set
    Fragment offset: 0
    Time to live: 249
    Protocol: UDP (0x11)
    Header checksum: 0x1e63 [correct]
    Source: 172.16.101.251 (172.16.101.251)
    Destination: 172.16.101.10 (172.16.101.10)
User Datagram Protocol, Src Port: 5060 (5060), Dst Port: 5060 (5060)
    Source port: 5060 (5060)
    Destination port: 5060 (5060)
    Length: 435
    Checksum: 0x6c94 [correct]
Session Initiation Protocol
    Request-Line: REGISTER sip:172.16.101.10 SIP/2.0
        Method: REGISTER
        Resent Packet: True
        Suspected resend of frame: 34
    Message Header
        Via: SIP/2.0/UDP 192.168.10.52:5060;branch=z9hG4bK9749dfca14c0ffb2
        From: 23456 <sip:23456@172.16.101.10;user=phone>;tag=2971075767
            SIP Display info: 23456
            SIP from address: sip:23456@172.16.101.10
            SIP tag: 2971075767
        To: 23456 <sip:23456@172.16.101.10;user=phone>
            SIP Display info: 23456
            SIP to address: sip:23456@172.16.101.10
        Call-ID: 3431569068@192.168.10.52
        CSeq: 1 REGISTER
        Contact: 23456 <sip:23456@192.168.10.52:5060;user=phone;transport=udp>;expires=300
            Contact Binding: 23456 <sip:23456@192.168.10.52:5060;user=phone;transport=udp>;expires=300
                URI: 23456 <sip:23456@192.168.10.52:5060;user=phone;transport=udp>
                    SIP Display info: 23456
                    SIP contact address: sip:23456@192.168.10.52:5060
        User-Agent: Cisco ATA 186  v3.2.1 atasip (050616A)
        Content-Length: 0
 
No.     Time        Source                Destination           Protocol Info
    533 152.674292  172.16.101.10         172.16.101.251        SIP      Status: 401 Unauthorized    (0 bindings)
 
Frame 533 (432 bytes on wire, 432 bytes captured)
    Arrival Time: Nov  3, 2005 11:32:02.281970000
    Time delta from previous packet: 0.001347000 seconds
    Time since reference or first frame: 152.674292000 seconds
    Frame Number: 533
    Packet Length: 432 bytes
    Capture Length: 432 bytes
    Protocols in frame: eth:ip:udp:sip
Ethernet II, Src: Dell_17:ea:82 (00:14:22:17:ea:82), Dst: Cisco_b5:15:f0 (00:04:c1:b5:15:f0)
    Destination: Cisco_b5:15:f0 (00:04:c1:b5:15:f0)
    Source: Dell_17:ea:82 (00:14:22:17:ea:82)
    Type: IP (0x0800)
Internet Protocol, Src: 172.16.101.10 (172.16.101.10), Dst: 172.16.101.251 (172.16.101.251)
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x60 (DSCP 0x18: Class Selector 3; ECN: 0x00)
        0110 00.. = Differentiated Services Codepoint: Class Selector 3 (0x18)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 418
    Identification: 0x0000 (0)
    Flags: 0x04 (Don't Fragment)
        0... = Reserved bit: Not set
        .1.. = Don't fragment: Set
        ..0. = More fragments: Not set
    Fragment offset: 0
    Time to live: 64
    Protocol: UDP (0x11)
    Header checksum: 0x9988 [correct]
    Source: 172.16.101.10 (172.16.101.10)
    Destination: 172.16.101.251 (172.16.101.251)
User Datagram Protocol, Src Port: 53492 (53492), Dst Port: 5060 (5060)
    Source port: 53492 (53492)
    Destination port: 5060 (5060)
    Length: 398
    Checksum: 0x0ad1 [correct]
Session Initiation Protocol
    Status-Line: SIP/2.0 401 Unauthorized
        Status-Code: 401
        Resent Packet: True
        Suspected resend of frame: 480
    Message Header
        Via: SIP/2.0/UDP 192.168.10.52:5060;received=172.16.101.251;branch=z9hG4bK9749dfca14c0ffb2
        Call-ID: 3431569068@192.168.10.52
        From: 23456 <sip:23456@172.16.101.10;user=phone>;tag=2971075767
            SIP Display info: 23456
            SIP from address: sip:23456@172.16.101.10
            SIP tag: 2971075767
        To: 23456 <sip:23456@172.16.101.10;user=phone>
            SIP Display info: 23456
            SIP to address: sip:23456@172.16.101.10
        CSeq: 1 REGISTER
        WWW-Authenticate: DIGEST realm="CISCO", nonce="4369a82d", qop="auth", algorithm=MD5
        Content-Length: 0
 
Ritesh Jalan