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New Member

SIP ALG - IOS F/W Enhancement

Hi there,

New to SIP and SIP ALG.

Just wondering, what is needed to activate SIP ALG in IOS F/W 12.4(22)T?

Thank you in advance.

New Member

Re: SIP ALG - IOS F/W Enhancement

Has anyone here tried SIP ALG in IOS 12.4(22)T? Please share some tips?

Appreciate it indeed.


Re: SIP ALG - IOS F/W Enhancement

I don't troubleshoot the firewall side of SIP every week, but from what I can tell our SIP NAT ALG has been stable for a while. I very rarely see issues with our SIP NAT ALG ( although I don't work on the firewall team), and I would put my trust in it. Even more so if you're going through an ATA. After 12.3 mainline or so, it hasn't given me any problems.

New Member

Re: SIP ALG - IOS F/W Enhancement

Nicmath, thanks for your input.

However as far as i know SIP ALG is a new feature to IOS, only available from 12.4(15)T onward. I might be wrong since I only started looking into SIP trunk very recently.

Thanks again.

Re: SIP ALG - IOS F/W Enhancement

This document may be helpful for you:

This feature has been around since 12.2(8)T it appears, which has become quite a mature feature.

I can assure if the feature had just been implemented in 12.4(15)T my opinion would be different.