Linksys SPA9000 Administration Guide

Linksys Voice System Administration Guide 43
Firewalls and SIP
Configuring the SPA9000 for ITSP Interoperability
3. Scroll down to the NAT Support Parameters section, and then enter the following settings to
enable and support the STUN server settings:
• Handle VIA received, Insert VIA received, Substitute VIA Addr: yes
• Handle VIA rport, Insert VIA rport, Send Resp To Src Port: yes
• STUN Enable: Choose yes.
• STUN Server: Enter the IP address for your STUN server.
4. Click Voice tab > Line N, where N is the number of the line interface for the ITSP service that
you need to configure.
5. Scroll down to the NAT Settings section.
• NAT Mapping Enable: Choose YES.
• NAT Keep Alive Enable: Choose YES (optional).
NOTE: Your ITSP may require the SPA9000 to send NAT keep alive messages to keep the
NAT ports open permanently. For more information, see Appendix A, "Advanced Topics
in LVS Administration," ”SIP-NAT Interoperation” section on page 135.
6. Click Submit All Changes.
NOTE: You also need to configure the firewall settings on your router to allow SIP traffic. See
”Firewalls and SIP,” on page 43.
Firewalls and SIP
To enable SIP requests and responses to be exchanged with the SIP proxy at the ITSP, you must
ensure that your firewall allows both SIP and RTP unimpeded access to the Internet.
• Make sure that the following ports are not blocked:
– SIP ports—UDP port 5060 through 5063, which are used for the SPA9000 line
interfaces
– RTP ports—16384 to 16482
• Also disable SPI (Stateful Packet Inspection) if this function exists on your firewall.

Linksys SPA9000 Specifications

Physical Interfaces

Ethernet ports	2 10/100BaseT RJ-45
Phone ports	2 RJ-11 FXS
Ring voltage	40-55 VRMS
Ring frequency	10 Hz - 40 Hz
Maximum ringer load	3 REN

Power

On-hook voltage	-50 V NOMINAL
Off-hook current	25 mA min
Terminating impedance	Configurable, including 600 ohms