Linksys VGA2100 - One Analog Voice Gateway 3 Line Administration Manual page 118

Linksys One Communications Solution
5
These sections help you configure firewall settings for the Linksys One network:
• Allowing Access to Network Services
• Adding DNS Names for Host Servers
• Deleting a Static IP Address
• Disabling External Access to Local Data Servers
• Exposing a Network Server as a DMZ Host
• Firewall Security (Application Layer Gateway for SIP)
911
? SIP messages should be properly NPAT'd to the WAN public address
assigned by the Service Provider.
? The FW shall provide Application Gateway support for all applicable
fields in SIP INVITE, BYE, CANCEL and resulting RTP media streams.
Chapter 5: Administering the Phone System
Managing Data Devices and Data Settings
SIP Application
Layer Gateway
looks into SIP
headers and
performs "fixup"
functions
SIP Proxy
Service Provider
Assigned Public
ALG ALG
IP Address
+
.2
Signaling
Media
FW
FW to act as SIP
Application
Gateway
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