From FB group Bell Telephone… Oct 28
Pat Chicas
We (at where I worked) used all Cisco 7900 sets. You can tap the help “?” button twice during a call and see the statistics for the call, both for a time (per second?) and cumulative. I would go to one bldg and make a call, and watch the errors accumulate. One of our guys said that it shouldn’t go over 100, usually just a few. Callers were complaining of ‘noisy handset’ like a bad coiled cord. Instead I was seeing error rates way over 100, sometimes over 2000. I found out the phones buffer the packets, but if the delay is too long the packets get dropped, and the caller hears either noise or a gap (dropout). The problems were from high traffic, caused by security cameras. We had to add fiber links between bldgs and the data center.
Easy for you to say, Pat Chicas. I was not involved with VoIP call manager, I was the guy who had to watch out that I didn’t get poked in the eye by a T-bar wire. The switches we were using were Cisco 3650(?) with PoE, but we switched (no pun intended) to Brocades. We had other problems like PoE overload, and one other really stupid problem with PoE injectors. As far as I knew, the switches supported QoS, but when the pipes are too small, there’s nothing the switch can do about it. 😵
Joshua Perrella
VoIP Ugghh is right!
We had fax machines that were connected to the Cisco box in the data center. Many of the faxes were big Xerox WorkCentre machines. The cheap desktop faxes (Brother , etc.) would negotiate or renegotiate slower speeds if the VoIP system had too much delay or jitter. But those Xerox prima donnas would refuse to go slower, instead retry to send the fax for *weeks*. Really. So we had to get the Xerox tech out to set (or reset after a software update) the maximum fax speed to 4800 bps. Only then would they work halfway reliably.
Mike Sica
I don’t remember what the Ciscos were, might’ve been ATA. As far as I was concerned the only thing I had to deal with was the 110 blocks on the back board. And they were a pain, too, because they started out with port zero, not port 1.
As long as we kept the damn Xeroxes in line, things were halfway working. But if the users wanted to fax to another campus (or any other fax within the district phone system), they had to use the 5 digit phone number. If they dialed the full area code and number, the VoIP would use the path to the CO and back, thus it went through the ISDN trunks twice, and that caused too much delay, jitter, timing issues or whatever, and the fax would not work. So I had to indoctrinate the users to use only the 5 digit number.
We had the all-in-one Xerox WorkCentres that let us scan in documents and send them through emails to anyone anywhere. Much better than fax. I thought these would put the fax machines out of business. I thought the fax machines would be an anachronism, but they kept hanging on, due to state and federal grant requirements. One of the concerns was about student ID privacy, where departments could not share fax machines.
Mike Sica
We hired a guy who worked on the call manager for the local school district. He helped me learn some, even though his new job was not involved with the network. He told me that the school district was too cheap to upgrade the call manager software, so they were still running an old version. I’m guessing this happens at a lot of other organizations, too. We were buying new 7942 sets for a couple hundred apiece. I went on eBay and found lots of ten used sets for the price of one new one. I figured we could buy a used set, throw it away and keep the handset and it would still be cheaper than a new handset. So rather than spend $$ on software updates, they were wasting it on phones.
