optical gear cooling requirements

Wed Mar 4 21:47:28 UTC 2015

>> On Tue, 03 Mar 2015 20:52:44 -0500, Martin Hannigan 
>> <hannigan at gmail.com>
>> wrote:
>>> Remember the Ascend MAX TNT and the sideways left-right airflow?
>> ...
>> 
>> Indeed I do. I see you've heard the story of PSINet melting components 
>> as well.
>> 
>> We used USR(3Com) TotalControl hardware: vertical venting. The chimney 
>> effect was impressive. (65F in, 100+ -- sometimes 120 -- out.)

TotalControl stuff was a tank but to get the density you need, you had to give them "TotalControl" of all of your rack space.

>We used Livingston Portmaster 3 back in the day. Front to back ventilation, ran cool as a cucumber, plug it in and it just worked.
>Awesome gear until Lucent bought the company to kill the product in favor of their Ascend TNT space heaters.

Yep, we called them the "Livingstones" because they were stone age stuff but would never die.  We had TONS is issues with the Ascend stuff.  On the Ascend Max stuff we had a big problem with their power supplies blowing up.  After lots of research we found the same third party supplier and ordered the same voltage with twice the current capacity and had no more problems.  They refused to acknowledge that the power supplies were sized too small even after we proved it by replacing them with third party stuff.

We preferred the TotalControl stuff but in the days of the modem standards wars, certain modems worked better with Ascend and some with USR so we maintained some of both.  We were in firmware fix hell on both the USRs and the Ascends for a period of years.

Steven Naslund
Chicago IL