Issue: Lync 2010 mobility client gets disconnect frequently.
Error: There is no specific error.
Recently I have deployed mobility on Lync server 2010 and everything is fine. Deployment is successful, ports are open on firewall, DNS records available, certificate placed on HLB and revers proxy however once user logged on Lync 2010 mobile client, its gets disconnect frequently.
In my environment using Big IP (F5) for reverse proxy.
Initially I feel issue with deployment however all test shows proper result even DNS, certificate, F5 forwarding etc.
When I look on deployment guide then I got to know the issue and fix.
Resolution is nothing to do with Lync server or DNS etc. it’s related to load balancer.
When request come to HLB it was forwarding those request however there were no reference get saved or stored. Microsoft clearly mentioned on document that, If your environment includes a Front End pool, the external Web Services virtual IPs (VIPs) on the hardware load balancer used for Web Services traffic must be configured for cookie-based persistence. Cookie-based persistence ensures that multiple connections from a single client are sent to one server to maintain session state. The cookies must meet specific requirements. This cookie requirements, mentioned under deployment guide under load Balancing Requirements.
If you plan to support Lync mobile clients only over your internal Wi-Fi network, you should configure the internal Web Services VIPS for cookie-based persistence as described for external Web Services VIPs. In this situation, you should not use source_addr persistence for the internal Web Services VIPs on the hardware load balancer.
In my environment has both internal and external web services so used cookie-based persistence for VIPs and issue got resolved.