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Help Picking IOS

I am in the process of upgrading a 3825 from SP Services to Advanced IP Services.

Currently running: 123-11.T5.bin

If I understand correctly, the T series are for new features while the mainline incorporates new features from the previous T series and incorporates only bug fixes in new releases.

I have narrowed my choices to:




I would really appreciate any input on which might be the best choice. Is 12.4 mainline considered the most stable or should I avoid that? If I stick with 12.3T should I stick with 11 or upgrade to the 14 release.



Re: Help Picking IOS

I would stay away from new releases, as they may fix one problem, but doesnt mean, they wont generate a new problem for you. But some times there is no choice left, when you are facing a bug in your existing software version, and the only way to fix it is to move to a newer version.

I have run 12.3.14T for a few voice deployments without issues, but again, each installation is unique. Both 12.3.11 ad 12.3.14 are out there for download and I have been happy with 12.3.14 so far.

Recently a customer had a VPN issue and he was running 12.3.14 (dont remember the T revision number) and his problem was fixed only by upgrading to 12.4.3a.

The decision to move away from T train or stay with T train, totally depends on whether the newer IOS version you are moving to is stable, dont have any major caveats, as well as whether it supports all your hardware (including wics and nm's).

12.4.3a is very stable, with my experience with it in the last few deployments. If you still prefer a T train in 12.4, 12.4.4T is out now, but it just came out. You never know what problems it will fix, while breaking a few others.

Good luck!

New Member

Re: Help Picking IOS

I've got to upgrade at least to 12.3.11T. I want the most stable release as this is a production box that supports voice and data. I'm leaning towards 12.4 since I think it should be better than the 12.3T development train. Any thoughts?

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