Can the Netscreen 5GT adsl be configured as a firewall without using the adsl modem

I have a Netscreen 5GT adsl which constantly drops the adsl connection. My ISP cannot see this
and reports the connection as having been up for days even when you can see from the 5GT logs that
that it is being dropped every few minutes.
I want to replace the onbaord adsl modem with another external one to see if the problem goes away but am not sure if it is possible to configure one of the ports as untrusted to allow the firewall to function.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Qlemo"Batchelor", Developer and EE Topic AdvisorCommented:
AFAIK the ADSL is only optional.
Whenever you have another network interface, and can assign Untrust zone to it, you won't need the ADSL part.

If ADSL drops, it is a protocol issue in most cases. I can't remember exactly which one are available, but there are some you can tweak. Take a look into your ADSL settings, and then ask the ISP for details about them. Maybe that gets you sorted.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Not 100% sure if you can assign untrust zone to an ethernet interface on NS5gt-ADSL [without using port mode]; if you can; then as already told by Qlemo it would act like a normal firewall.

If you cannot; but have extended licenses and can change the firewall port mode to dual-untrust mode;  then you should be able to use the firewall like a normal 5gt.

Thank you.
Correction; dual untrust port mode cannot be enabled on ns5gt-adsl:
bigwombleAuthor Commented:
Many thanks to Qlemo and to dpk wal for their straightforward and very helpful answers. Much appreciated.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Hardware Firewalls

From novice to tech pro — start learning today.