Cisco Cisco 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
Expressway-C is configured with an internally resolvable name of expc.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
Expressway-C is configured with an internally resolvable name of expc.internal-domain.net (which resolves to an IP
address of 10.0.0.2 by the internal DNS servers).
Element
Role
Expressway-
C
C
SIP Registrar & Proxy and communications gateway for Unified CM.
EX90 and
EX60
EX60
Example endpoints hosted on the internal network which register to the Expressway-C or to the
Unified CM.
Unified CM.
DNS (local 1
& local 2)
& local 2)
DNS servers used by the Expressway-C 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.
Router
Acts as the gateway for all internal network devices to route towards the DMZ (to the NAT device
internal address).
internal address).
Cisco TMS
Server
Server
.
Unified CM
Endpoint devices can register to Unified CM. The Expressway acts as a Unified Communications
gateway for third-party devices and for mobile and remote access. Or you can register directly to the
Cisco Expressway-C.
gateway for third-party devices and for mobile and remote access. Or you can register directly to the
Cisco Expressway-C.
To configure the Expressway for Unified Communications services, see Mobile and Remote Access
via Cisco Expressway Deployment Guide on the
via Cisco Expressway Deployment Guide on the
.
Syslog
Server
Server
.
DMZ Network Element
Expressway-E
The Expressway-E is a SIP Proxy for devices which are located outside the internal network (for example, home users
and mobile worker registering to Unified CM across the internet and 3
and mobile worker registering to Unified CM across the internet and 3
rd
party businesses making calls to, or receiving
calls from this network).
The Expressway-E is configured with a traversal server zone to receive communications from the Expressway-C 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 Expressway-E has a public network domain name. For example, the Expressway-E is configured with an
externally resolvable name of expe.example.com (which resolves to an IP address of 192.0.2.2 by the external /
public DNS servers).
externally resolvable name of expe.example.com (which resolves to an IP address of 192.0.2.2 by the external /
public DNS servers).
10
Cisco Expressway-E and Expressway-C - Basic Configuration Deployment Guide
Introduction