I was working with deploying mobility on Lync server 2010 and verified everything is fine, 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.
I'm using Big IP (F5) for reverse proxy. I was searching solution in bolgs, Technet etc. after 2-3 hours checked the deployment guide then i got some help to resolve the issue. Issue was in Load balancer.
When request come to HLB it was forwarding those 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.