Issue: Lync Federation is working on one way.
Error: There is no specific error however unable to IM and see presence of federated partner other side.
Federated Lync with partner company Lync. However I am able to Instance Message and see the presence information of my partner Lync user however they cannot my presence and unable to reply my IM.
Following things need to check to resolve the issue.
1. Lync Federation working from one side means federation setup properly and issue with something else.
2. In this scenarios two major things need to check. 1. 5061 port 2. DNS resolution.
3. Log on to Lync Edge server and try to telnet partner company access edge 5061 port. [Try to telnet from problematic (user unable to IM and see presence) Lync edge server].
E.g. telnet accessedge.domain.com 5061
4. If you are unable to telnet using access edge name then try to telnet using IP instead of name.
E.g. telnet 10.20.30.40 5061
5. If you are able to telnet using IP address instead of access edge name then problem with DNS on server edge server which are not getting resolution properly.
6. In my case issue with DNS, I was able to telnet both 5061 and 443 using access edge IP address however unable to do using name.
7. Means ports are open however DNS resolution not happening on Edge server.
8. Corrected the DNS issue on Edge server to resolve the external records.
9. Now able to telnet using name and IP to partner access edge using 5061 and 443 port.
10. After correct DNS issue Lync communication started from both end without issue.
Few more points need to verify on edge server.
a. Check the Host file on edge server and add the FE server IP with name and pool name FE server IP with pool name.
b. If you have director the same director IP with name and Director IP with director pool name both.
c. If you have backup pool and then add the same FE IP with server name and pool name to edge server host file.