Using The Spa9000 With A Firewall Or Router; Spa400 Sip-Pstn Gateway - Linksys SPA9000 Administration Manual

Using the SPA9000 with a Firewall or Router

When using the SPA9000 behind a firewall or router, make sure that the following ports are not
blocked:
SIP ports—By default, UDP ports 5060 through 5063
RTP ports—16384 to 16482
Also disable SPI if this function exists on your firewall.

SPA400 SIP-PSTN Gateway

When a local user on the SPA9000 network initiates a call to a PSTN subscriber, the SPA400 acts
as the SIP-PSTN gateway, which converts the SIP and RTP media packets into the appropriate
signal for transmission to the PSTN switch. For example, if UserA calls UserD, the SIP request is
routed by the SIP proxy in the SPA9000 to the SPA400 (see
UserA
The SPA400 then converts the SIP and RTP packets it receives from UserA and the signals it
receives from the PSTN switch.
Linksys Voice System Administration Guide
Figure A-3 The SPA400 as a SIP-PSTN Gateway
PSTN
UserD
1 to 4 DID lines
SPA400
SIP-PSTN
UserB
Gateway
Switch
Internet (WAN) Interface
SPA9000
SIP Proxy
Technology Background
Figure A-3).
133