Which option changes the addresses and ports in voice and video signaling messages?

The correct answer is D. NAT ALG. NAT ALG (Application Layer Gateway) operates at the application layer and understands specific protocols like SIP and H.323. It inspects signaling messages and rewrites the embedded IP addresses and port numbers within the message payload to reflect the NATted (translated)…

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Question

Options

AFirewall ALG
BNAT overload
CNAT Pinhole
DNAT ALG

How the community answered

(39 responses)

A
3% (1)
B
5% (2)
D
92% (36)

Explanation

NAT ALG (Application Layer Gateway) operates at the application layer and understands specific protocols like SIP and H.323. It inspects signaling messages and rewrites the embedded IP addresses and port numbers within the message payload to reflect the NATted (translated) values. This is critical for voice/video protocols because their signaling messages carry media endpoint information (IP/port) inside the packet body, not just in headers. NAT overload (PAT) only translates transport-layer headers. NAT Pinhole simply opens inbound ports. Firewall ALG is a closely related concept but NAT ALG specifically describes the function of rewriting addresses and ports inside application-layer signaling.

Topics

#NAT ALG#Network Address Translation#Voice and Video Signaling#Collaboration Networking

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