[c-nsp] Cisco 7960 7940 voip phones

[Brian McMahon]

On Apr 6, 2006, at 10:07, Cisco Sheep wrote:

> I attempted that solution and at that point I no longer can  
> communicate
> with my phone system. I also am not using any fancy switches just a  
> hub
> and an open source phone box.

My lab setup is scrounged 7900 phones and an Asterisk PBX.  Can't  
afford that fancy CallManager stuff on a California community college  
budget.  8-)

Does "hub" mean *hub*, as in layer 1 multiport repeater?  If so, you  
may be suffering from another problem that I found the Hard Way(*).   
At least some of the 7900 phones appear to insist on doing full- 
duplex, whether they negotiated it or not.

(*)The Hard Way: Specifically, the Cat2950, which (quite properly)  
had set half duplex, and therefore classic CSMA/CD, on the port,  
eventually decided to error-disable it due to excessive collisions.   
I think it was a 7912G that I "discovered" this on.  YMMV.

-- 
Brian McMahon <brian dot mcmahon at cabrillo dot edu>
Computer Networking and System Administration Instructor
Cabrillo College, Aptos, California