Cisco Cisco Administrative Workstation Installation Guide

Each central site must have its own Signaling Access Network (SAN). The ICM 
system uses the Signaling Access Network to communicate with the IXC 
signaling network. The Signaling Access Network for the MCI, AT&T, Nortel, 
and Stentor NICs is implemented as an Ethernet LAN. This LAN is separate from 
the ICM private LAN. 

In Sprint NIC configurations, the Signaling Access Network is implemented via 
Eicon X.25 WAN cards on the CallRouter platform. These cards allow the ICM 
system to connect the IXC signaling network. The X.25 links to the IXC signaling 
network are considered the Signaling Access Network. In these configurations, 
the separate Ethernet Signaling Access Network is not required.

 shows a typical Signaling Access Network for a single central site. It 

assumes that the two sides are geographically separated. 

The IP addresses shown in this and subsequent figures are examples only. Use 
addresses specific to your networks.

TCP

If the source address is the local 
CallRouter’s high priority 
address or the destination 
address is the other CallRouter’s 
high priority address.

All other TCP packets.

UDP

If source or destination port 
number is in the range 
39000–39999.

1

1.

 If you cannot configure the IP router to assign priority based on a range of port numbers, then 
assign a high priority to all UDP packets.

All other UDP packets.