Cisco Cisco TelePresence Video Communication Server Expressway
Network elements
Internal network elements
The internal network elements are devices which are hosted on the organization’s local area network.
Elements on the internal network have an internal network domain name. This internal network domain name
is not resolvable by a public DNS. For example, the VCS Control is configured with an internally resolvable
name of vcsc.internal-domain.net (which resolves to an IP address of 10.0.0.2 by the internal DNS servers).
is not resolvable by a public DNS. For example, the VCS Control is configured with an internally resolvable
name of vcsc.internal-domain.net (which resolves to an IP address of 10.0.0.2 by the internal DNS servers).
VCS Control
The VCS Control is a SIP Registrar & Proxy and H.323 Gatekeeper for devices which are located on the
internal network.
internal network.
The VCS Control is configured with a traversal client zone to communicate with the VCS Expressway to
allow inbound and outbound calls to traverse the NAT device.
allow inbound and outbound calls to traverse the NAT device.
EX90 and EX60
These are example endpoints hosted on the internal network which register to the VCS Control.
DNS (local 1 & local 2)
DNS servers used by the VCS Control, to perform DNS lookups (resolve network names on the internal
network).
network).
DHCP server
The DHCP server provides host, IP gateway, DNS server, and NTP server addresses to endpoints located
on the internal network.
on the internal network.
Router
The router device acts as the gateway for all internal network devices to route towards the DMZ (to the NAT
device internal address).
device internal address).
Cisco TMS server
).
Syslog server
).
DMZ network element
VCS Expressway
The VCS Expressway is a SIP Registrar & Proxy and H.323 Gatekeeper for devices which are located
outside the internal network (for example, home users and mobile worker registering across the internet and
3
outside the internal network (for example, home users and mobile worker registering across the internet and
3
rd
party businesses making calls to, or receiving calls from this network).
The VCS Expressway is configured with a traversal server zone to receive communications from the VCS
Control in order to allow inbound and outbound calls to traverse the NAT device.
Control in order to allow inbound and outbound calls to traverse the NAT device.
The VCS Expressway has a public network domain name. For example, the VCS Expressway is configured
with an externally resolvable name of vcse.example.com (which resolves to an IP address of 192.0.2.2 by
the external / public DNS servers).
with an externally resolvable name of vcse.example.com (which resolves to an IP address of 192.0.2.2 by
the external / public DNS servers).
Cisco VCS Basic Configuration (Control with Expressway) Deployment Guide
Page 6 of 65
Introduction