[Serusers] SIP 477 error when registered with TCP

[mahesh]

Hi all,

I am using the following network configuration.

HOST1---NAT---Internet---HOST2

HOST1 and HOST2 are windows XP machines with SJPhone software. The NAT box
has SIP ALG(Application Level Gateway), which modifies the SIP packets to
replace the Private IP address with the Public IP address.

I am registering with iptel.org proxy server using TCP from both the
machines. I am able to make a call from HOST1 to HOST2. But when i try to
make a call from HOST2 to HOST1, i get an error which says, "477
Unfortunately error on sending to next hop occurred(477/TM)". When I
register using UDP, then i do not see this problem. Could someone tell me
what I am missing here.

Thanks
Mahesh