Cisco Cisco TelePresence Video Communication Server Expressway
Introduction
Cisco VCS Deployment Guide: Microsoft OCS 2007 R2, Lync 2010 and Cisco VCS X7.0
Page 9 of 104
up for the MCU domain), which has a single IP address for TCP connectivity and a single FQDN for
TLS connectivity.
TLS connectivity.
If using TLS and round-robin DNS for static route destinations, OCS/Lync server may change the VCS
peer that it sends calls to, but only at a maximum rate of change of once per 5 seconds. In Lync it
seems to keep sending all traffic to one VCS unless it loses connection to that VCS, and only then
does it swap to another VCS – so this provides resilience rather than load balancing.
peer that it sends calls to, but only at a maximum rate of change of once per 5 seconds. In Lync it
seems to keep sending all traffic to one VCS unless it loses connection to that VCS, and only then
does it swap to another VCS – so this provides resilience rather than load balancing.
Why add an “OCS/Lync Gateway” VCS Control?
The “OCS/Lync gateway” VCS is an interface between an existing working video network and the
Microsoft OCS/Lync environment. Using this gateway minimizes the changes that need to be made in
the video network so as to introduce as few artifacts as possible when adding OCS/Lync
interoperability to the video network.
Microsoft OCS/Lync environment. Using this gateway minimizes the changes that need to be made in
the video network so as to introduce as few artifacts as possible when adding OCS/Lync
interoperability to the video network.
Having dedicated VCSs for this “OCS/Lync gateway” operation limits the number of VCSs that the
Enhanced collaboration option key needs to be purchased for and enabled on.
Enhanced collaboration option key needs to be purchased for and enabled on.
The presence server residing on the OCS/Lync Gateway VCS publishes presence information into the
OCS/Lync environment via the B2BUA application. This presence server must be authoritative for the
domain shared by OCS/Lync and the VCS (ciscotp.com). It must also be authoritative for the video
domain (vc.ciscotp.com) and any dedicated MCU domains (mcu.ciscotp.com) in use, and hold the
presence status of endpoints specified in the FindMe users in the OCS/Lync Domain existing on this
“OCS/Lync gateway” VCS (cluster), as FindMe presence only represents the presence of devices
whose presence is known on that VCS (cluster).
OCS/Lync environment via the B2BUA application. This presence server must be authoritative for the
domain shared by OCS/Lync and the VCS (ciscotp.com). It must also be authoritative for the video
domain (vc.ciscotp.com) and any dedicated MCU domains (mcu.ciscotp.com) in use, and hold the
presence status of endpoints specified in the FindMe users in the OCS/Lync Domain existing on this
“OCS/Lync gateway” VCS (cluster), as FindMe presence only represents the presence of devices
whose presence is known on that VCS (cluster).
For calls into OCS/Lync (from whichever video endpoint the user wants to call from) to have a Caller
ID / call back ID that works, FindMe must re-write the caller ID of calls to OCS/Lync with the relevant
OCS/Lync SIP user ID. For FindMe to be able to do this, calls must be routed through the Cisco VCS
holding the relevant FindMe; having an “OCS/Lync gateway” helps funnel all calls through the correct
place.
ID / call back ID that works, FindMe must re-write the caller ID of calls to OCS/Lync with the relevant
OCS/Lync SIP user ID. For FindMe to be able to do this, calls must be routed through the Cisco VCS
holding the relevant FindMe; having an “OCS/Lync gateway” helps funnel all calls through the correct
place.
OCS/Lync Server can only send calls to:
Cisco VCSs that have “same domain” FindMe users registered to the OCS/Lync Server;
OCS/Lync Server sends the call to the VCS that is registering that user
OCS/Lync Server sends the call to the VCS that is registering that user
a single FQDN (though this may have a round robin DNS address to support a cluster of Cisco
VCSs for resilience) for calls to MCUs accessible via a static domain route defined in OCS/Lync
Server.
VCSs for resilience) for calls to MCUs accessible via a static domain route defined in OCS/Lync
Server.
OCS/Lync server will only accept messages that it has been configured to trust. Having a dedicated
“OCS/Lync gateway” VCS or Cisco VCS cluster also limits the number of trusted devices that need to
be configured in OCS/Lync, as every device that sends SIP messages to OCS/Lync server needs to
be explicitly listed as a trusted host in OCS/Lync server.
“OCS/Lync gateway” VCS or Cisco VCS cluster also limits the number of trusted devices that need to
be configured in OCS/Lync, as every device that sends SIP messages to OCS/Lync server needs to
be explicitly listed as a trusted host in OCS/Lync server.
“OCS/Lync gateway” and multiple OCS/Lync domains
If OCS/Lync supports multiple domains, and the video network is to support these domains as well, it
is recommended that one “OCS/Lync gateway” VCS or VCS cluster is used to handle each domain as
B2BUA only supports registering a single domain.
is recommended that one “OCS/Lync gateway” VCS or VCS cluster is used to handle each domain as
B2BUA only supports registering a single domain.
If some domains are not used in the video network, but need calls to be routed to them, there does not
need to be a “OCS/Lync gateway” VCS for those domains – Search rules can be added to support
routing to these domains.
need to be a “OCS/Lync gateway” VCS for those domains – Search rules can be added to support
routing to these domains.
If different OCS/Lync SIP domains are handled by different “OCS/Lync gateway” VCSs or VCS
clusters, take care to ensure that each “OCS/Lync gateway” VCS or VCS cluster is authoritative
for the presence information that is required for the B2BUA registered FindMe users for that one
shared domain and all endpoints that are referenced by those FindMe entries.
clusters, take care to ensure that each “OCS/Lync gateway” VCS or VCS cluster is authoritative
for the presence information that is required for the B2BUA registered FindMe users for that one
shared domain and all endpoints that are referenced by those FindMe entries.