Cisco Cisco Expressway
Introduction
This deployment guide describes how to configure a Cisco Collaboration video network to interwork with a Microsoft
Lync environment, using the back to back user agent (B2BUA) on the Cisco Expressway (Expressway).
Lync environment, using the back to back user agent (B2BUA) on the Cisco Expressway (Expressway).
It also highlights the capabilities and limitations of interoperation of Expressway and Lync.
To enable video calling and desktop sharing between Cisco Unified Communications Manager-registered
collaboration endpoints and Lync clients, you need to configure:
collaboration endpoints and Lync clients, you need to configure:
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A SIP trunk between the Gateway Expressway and Unified CM
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The Lync B2BUA on the Gateway Expressway to route calls to Lync
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Static routes from Lync to the Gateway Expressway
Deployment Scope
The following major Expressway-based deployments are mutually exclusive. They cannot be implemented together
on the same Expressway (or traversal pair):
on the same Expressway (or traversal pair):
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Mobile and Remote Access
■
Microsoft Lync Interoperability
■
Jabber Guest
What is the Gateway Expressway and Why Should I Use It?
A Gateway Expressway is an Expressway-C (or cluster of Expressway-Cs) that provides interoperability between a
Cisco Collaboration network and the Microsoft Lync environment.
Cisco Collaboration network and the Microsoft Lync environment.
We require that you dedicate an Expressway-C to this role so that you:
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Minimize the impact of adding Lync interoperability to your existing Cisco Collaboration network.
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Limit the number of Expressways that need the Microsoft Interoperability option key.
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Reduce the number of static routes that you need to define from the Lync environment.
Each static route matches a single SIP domain to a single FQDN, or IP address, but you can create appropriate
DNS records to map this destination to a cluster of Expressways.
DNS records to map this destination to a cluster of Expressways.
■
Reduce the number of third-party applications that you configure Lync to trust.
Lync Server will only accept SIP messages from peers that it trusts. By dedicating a Gateway Expressway (or
cluster), you reduce the number of trusted devices that you need to configure in Lync.
cluster), you reduce the number of trusted devices that you need to configure in Lync.
Recommendations
■
We recommend that you use TLS connectivity throughout the deployment. We do not recommend
TCP because:
TCP because:
—
Lync uses TLS by default
—
TCP prevents the use of encryption
—
TCP may not work for Lync Server environments that include hardware load balancers (HLBs) and / or Lync
Director
Director
—
A static route using TCP must go to the destination IP address. So, with TCP you cannot get redundancy
from a clustered Gateway Expressway, which you can when you configure a TLS static route to the
cluster's FQDN
from a clustered Gateway Expressway, which you can when you configure a TLS static route to the
cluster's FQDN
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Cisco Expressway with Microsoft Lync Deployment Guide