Andreas Granig wrote:
Juha Heinanen wrote:
in summary: a load balancing solution that at the same time is redundant is not possible using the participating sers alone. some intelligent front end help is needed and i'm not convinced yet that even that could be done.
What about this (maybe a special case):
I was just thinking about STUN, and AFAIK this relies on a NAT device not matching the source IP of a datagram, so the client opens a NAT binding to an STUN server to determine an external IP/port pair which is filled in the Contact header. The Proxy then can also send SIP requests to this external IP/port which is forwarded to the client by the NAT device. Is this basically correct?
If so, it theoretically should work with transparent NAT handling on two SERs too, if both SERs know the external IP/port of UAC-1.
That's fine. There is no problem with STUN-traverseable NATs. But there are problems with symmetric NAT and restricted NAT.
I also think I know now why it didn't work for me: SER-1 got the request from UAC-1 and stored the contact IP and the received IP in the location table. SER-2 got the replicated register but stored SER-1's IP as received IP:
True, ser-2 does not use fix_... for REGISTERs received from ser-1.
regards, klaus