Cisco Cisco TelePresence Video Communication Server Expressway
Network Elements
Internal Network Elements
The internal network elements are devices which are hosted on your local area network. Elements on the internal
network have an internal network domain name. This 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).
network have an internal network domain name. This 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).
Element
Role
VCS Control
SIP Registrar & Proxy and H.323 Gatekeeper for devices which are located on the internal
network.
network.
EX90 and EX60
Example endpoints hosted on the internal network which register to the VCS Control.
DNS (local 1 &
local 2)
local 2)
DNS servers used by the VCS Control to perform DNS lookups (resolve network names on the
internal network).
internal network).
DHCP Server
Provides host, IP gateway, DNS server, and NTP server addresses to endpoints located on the
internal network.
internal network.
Router
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
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.
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).
externally resolvable name of vcse.example.com (which resolves to an IP address of 192.0.2.2 by the external /
public DNS servers).
External Network Elements
Element
Role
EX60
An example remote endpoint, which is registering to the VCS Expressway via the internet.
DNS (Host)
The DNS owned by the service provider which hosts the external domain example.com.
DNS (external 1 &
external 2)
external 2)
The DNS used by the VCS Expressway to perform DNS lookups.
NTP server pool
An NTP server pool which provides the clock source used to synchronize both internal
and external devices.
and external devices.
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Cisco VCS Expressway and VCS Control - Basic Configuration Deployment Guide
Introduction