Nat Mapping With Session Border Controller; Nat Mapping With Sip-Alg Router; Configuring Nat Mapping With A Static Ip Address - Cisco SPA942 - - IP Phone Administration Manual

5
NOTE
STEP 1
STEP 2
110

NAT Mapping with Session Border Controller

It is strongly recommended that you choose an ITSP that supports NAT mapping
through a Session Border Controller. With NAT mapping provided by the ITSP, you
have more choices in selecting a router.

NAT Mapping with SIP-ALG Router

If the ITSP network does not provide a Session Border Controller functionality, you
can achieve NAT mapping by using a router that has a SIP ALG (Application Layer
Gateway). The WRV200 router is recommended for this purpose, although any
router with a SIP-ALG can be used. By using a SIP-ALG router, you have more
choices in selecting an ITSP.

Configuring NAT Mapping with a Static IP Address

If the ITSP network does not provide a Session Border Controller functionality, and
if other requirements are met, you can configure NAT mapping to ensure
interoperability with the ITSP.
Requirements
• You must have an external (public) IP address that is static.
• The NAT mechanism used in the router must be symmetric. See
Whether the Router Uses Symmetric or Asymmetric NAT," on page
• The LAN switch must be configured to enable Spanning Tree Protocol and Port
Fast on the ports to which the SPA devices are connected.
Use NAT mapping only if the ITSP network does not provide a Session Border
Controller functionality.
Click Admin Login and advanced.
Click the SIP tab.
Configuring SIP, SPCP, and NAT
Network Address Translation (NAT) and Cisco IP Phones
Cisco SPA and Wireless IP Phone Administration Guide
"Determining
113.