Hi,
 
I'm doing some testing with SER and recently noticed that some NOTIFY activity seems to be going in an eternal loop at our server. 14 SIP NOTIFY Requests were found to loop back and forth between host.domain.com and w.x.y.z where host.domain.com is our server's FQDN and w.x.y.z its IP. The extract of tcpdump output below shows how it looks like. Would greatly appreciate if someone could help me understand what I am seeing; What can have caused this? Could it be a result of bad routing logic?
 
 

02:19:28.720999 host.domain.com.5060 > w.x.y.z.5060:  udp 461 (DF) [tos 0x10]

02:19:28.721020 host.domain.com.5060 > w.x.y.z.5060:  udp 584 (DF) [tos 0x10]

02:19:28.721032 host.domain.com.5060 > w.x.y.z.5060:  udp 707 (DF) [tos 0x10]

02:19:28.721044 host.domain.com.5060 > w.x.y.z.5060:  udp 830 (DF) [tos 0x10]

02:19:28.721056 host.domain.com.5060 > w.x.y.z.5060:  udp 953 (DF) [tos 0x10]

02:19:28.721068 host.domain.com.5060 > w.x.y.z.5060:  udp 1076 (DF) [tos 0x10]

02:19:28.721081 host.domain.com.5060 > w.x.y.z.5060:  udp 1199 (DF) [tos 0x10]

02:19:28.721093 host.domain.com.5060 > w.x.y.z.5060:  udp 1322 (DF) [tos 0x10]

02:19:28.721107 host.domain.com.5060 > w.x.y.z.5060:  udp 1445 (DF) [tos 0x10]

02:19:28.721135 host.domain.com.5060 > w.x.y.z.5060:  udp 1568 (frag 56776:1480@0+) [tos 0x10]

02:19:28.721158 host.domain.com.5060 > w.x.y.z.5060:  udp 1691 (frag 56777:1480@0+) [tos 0x10]

02:19:28.721181 host.domain.com.5060 > w.x.y.z.5060:  udp 1814 (frag 56778:1480@0+) [tos 0x10]

02:19:28.721204 host.domain.com.5060 > w.x.y.z.5060:  udp 1937 (frag 56779:1480@0+) [tos 0x10]

02:19:28.721225 host.domain.com.5060 > w.x.y.z.5060:  udp 2060 (frag 56780:1480@0+) [tos 0x10]

02:19:28.721415 w.x.y.z.5060 > host.domain.com.5060:  udp 461 (DF) [tos 0x10]

02:19:28.721475 w.x.y.z.5060 > host.domain.com.5060:  udp 584 (DF) [tos 0x10]

02:19:28.721585 w.x.y.z.5060 > host.domain.com.5060:  udp 707 (DF) [tos 0x10]

02:19:28.721704 w.x.y.z.5060 > host.domain.com.5060:  udp 830 (DF) [tos 0x10]

02:19:28.721843 w.x.y.z.5060 > host.domain.com.5060:  udp 953 (DF) [tos 0x10]

02:19:28.721981 w.x.y.z.5060 > host.domain.com.5060:  udp 1076 (DF) [tos 0x10]

02:19:28.722136 w.x.y.z.5060 > host.domain.com.5060:  udp 1199 (DF) [tos 0x10]

02:19:28.722301 w.x.y.z.5060 > host.domain.com.5060:  udp 1322 (DF) [tos 0x10]

02:19:28.722472 w.x.y.z.5060 > host.domain.com.5060:  udp 1445 (DF) [tos 0x10]

02:19:28.722507 w.x.y.z.5060 > host.domain.com.5060:  udp 1568 (frag 56776:96@0+) [tos 0x10]

02:19:28.722824 w.x.y.z.5060 > host.domain.com.5060:  udp 1691 (frag 56777:224@0+) [tos 0x10]

02:19:28.722961 w.x.y.z.5060 > host.domain.com.5060:  udp 1814 (frag 56778:344@0+) [tos 0x10]

02:19:28.723165 w.x.y.z.5060 > host.domain.com.5060:  udp 1937 (frag 56779:472@0+) [tos 0x10]

 
 
 
Regards,
Mansur Ali Abbasi