Firewall Configuration
SIP
Cisco SA500 Series Security Appliances Administration Guide 129
4
SIP
SIP ALG (Session Initiation Protocol Application-level gateway) can rewrite
information within the SIP messages (SIP headers and SDP body) to make
signaling and audio traffic between the client behind NAT and the SIP endpoint
possible.
NOTE SIP-ALG should be enabled when voice devices such as the UC 500 or SIP phones
are connected to the network behind the security appliance.
STEP 1 Click Firewall > SIP.
The SIP ALG window opens.
STEP 2 Check the box to enable SIP ALG support or uncheck the box to disable this
feature. If this feature is disabled, the router will not allow incoming calls to the UAC
(User Agent Client) behind the router.
STEP 3 Click Apply to save your settings.