IPSEC ALG

I have no background in networking so was hoping comeone can help
answer some questions in layman's terms.

I have noticed the following custom service on my Westell 327W router.
My DSL provider (verizon) states it was not installed as part of their
service. I recently installed Norton Internet Security and am trying
to determine if it was cretated as part of that program's installation
process. I have not heard back yet from Symantec. Here's the service
description

Service Name Service Mode Host Device
IPSEC ALG Client Dynamic

Port 1
Protocol: TCP/UDP
Global Port(s): 500
Base Host Port: 500

I have no idea what this service is supposed to do. I don't recall it
being present the first time I setup my DSL service, and it is defined
as a custom service. I did not add the service.

I would appreciate it if someone could explain to me what this does.
can I delete it? I am trying to setup placeshifting (TV) with a home
pc and am experiencing difficulty getting the remote server to see the
home PC (Port 80 unreachable) even though I added a custom service for
port forwarding on port 80, disabled the router firewall, and ensured
windows xp firewall had exceptions for the remote software, and set up
a static IP on the pc with the tv card.

Appreciate any help that can be offered.

happy holidays

dts