Cisco SPA-841 - Sipura VoIP Phone Administration Manual page 52

Configuring Your System for ITSP Interoperability
Network Address Translation (NAT) and Voice over IP (VoIP)
NOTE
STEP 1
STEP 2
STEP 3
STEP 4
STEP 5
SPA9000 Voice System Administration Guide
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.
Connect to the administration web server, and choose Admin access with
Advanced settings.
Click Voice tab > SIP.
Scroll down to the NAT Support Parameters section, and then enter the following
settings to support static mapping to your public IP address:
•
Handle VIA received, Insert VIA received, Substitute VIA Addr: yes
•
Handle VIA rport, Insert VIA rport, Send Resp To Src Port: yes
•
EXT IP: Enter the public IP address for your router.
Click Voice tab > Line
Scroll down to the NAT Settings section.
•
NAT Mapping Enable: Choose YES.
•
NAT Keep Alive Enable: Choose YES (optional).
Voice tab > SIP: NAT Support Parameters
N
, where N represents the line interface number.
3
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