Nortel 5520 Stack question

[baile58]

Currently I have a stack of 5 Nortel branded 5520-48T-PWR switches. I am looking to add an additional switch, but the newer 5520 series are all branded Avaya.

Part Number Nortel: AL1001A05-E5
Part Number Avaya: AL1001E05-E5

Couple of questions...

1. Will the new Avaya switches stack with the older Nortel switches.
2. Our stack is currently running version 5.1.1 - I assume the new Avaya switch will come with version 6.x. Is it possible to downgrade to version 5.1.1 or is it not even possible to run version 5.1.1 on the Avaya hardware?
3. If 1 & 2 are possible, is there any supporting documentation?

Thanks for you help in advance.

Edit: Added Part Numbers

[baile58]

Anyone know just the answer to question 1, will I be able to stack both a Nortel and Avaya switch together?

I have already called tech support, but since I don't have a support contract they can't answer my questions.

[gbeaudoin]

I think they will work together. Assuming matching firmware version of course. I belives you can even make a 55xx and a 56xx switch work togheter.

As for the product number, the only difference between the two is the power cord. A is without power cord. E is with a US power cord.

[wittersjohan]

Adding an Avaya branded unit to a stack is no problem, as the chassis hardware is still about the same, only the logo's have changed...

But you have to make sure the diag/agent are the same. The new unit will have a recent build and should theoretically be downgraded, but I personally usually do this myself as it is quicker and better manageable..

[baile58]

Answers

I answer my own thread. Yes, it is possible to stack both Avaya and Nortel switches. But they must be at the same software and diagnostic versions. Like others have pointed out, it's much easier to downgrade the new switch before adding it to the stack. The downgrade is the same procedure as the upgrade - software first, diagnostics second.

I ended up buying 2 Avaya switches - I added 1 about 4 weeks ago. It is number 6 in the switch stack and has been running clean since I downgraded and plugged it in.