Hi,
We are currently working on guidance for using LTM as the Lync reverse proxy. Although that guidance is not yet complete, I've successfully used a virtual server on an external BIG-IP to forward reverse proxy traffic to an internal virtual server that has director servers for pool members. With only one LTM, you could add a self IP to the same network that your Lync servers are on, and create a new external virtual server to grab the reverse proxy traffic and forward it on, which would require changing DNS to point clients at that virtual. With one virtual server, you could do it with an iRule that catches requests for the meet/dialin URLs and forwards that traffic to the internal server pool rather than the edge. Something like this might work:
when HTTP_REQUEST {
if { [HTTP::host] equals"meet.mydomain.com"} {
pool my_lync_reverse_proxy_pool
}
}