I have the following situation. I am getting packet loss on extended pings to 7960 and 7940 phones. I am averaging about 85% return even from the switches that the phones are plugged into. This packet loss is in direct correlation to voice quality issues from the same phones. I can take a 7912, put it in place of a 7960 or 40 and the packet loss disappears. Even if I give the phones the same IP addresses. Nothing else changes, not the VLANS, not the configs on the switch, nothing. Does anyone have an idea on what could be causing this? I am running the latest phone loads and have tried downgrading the phone loads with the same results. One last clue. The voice quality issue did not (so I am told) manifest itself until the phones were moved to a new cluster from 3.3 to 4.1. The supporting network infrastructure did not change at all though. Most but not all of the 7960s and 7940s have PCs connected but even the ones that don't still have the same problem. PLease bear in mind the issue goes away as soon as a 7912 is placed, even with a PC connected and NONE of the 7912s network wide seem to have this problem. All the phones were purchased over a long period of time so bad hardware should not be the issue
Long time... hope things (other than this) are going well for you! Can you please let us know the exact version of CCM and phone firmware you are running. I had a look for bugs that might be related to this, but it would help to narrow this down.
Have you tried putting a sniffer on to see what is happening? (probably)
I did come across one bug that was somewhat ambiguous that was in reference to problems created by the NIC settings on the CCM box being set to auto/auto.
thanks for the replies. Call Manager is 4.1(3)sr3b. It appears if I ping from a workstation not attached to the phone I don't get packet loss on the pings. I understand what you are saying about the switch being too fast but then why do I not get packet loss on pings from the 7912s? So far the voice quality issues go away when a 7912 is placed and come back with a 7960 is placed and I have tried different units to rule out hardware issues. Exact same results all the time.
You have me scratching my head on this one. What is the topolgy of this network and have you tried any sniffers? I am curious if you may have something on the network segment that is doing a DOS attack. I have been looking for documentation for differences in the 2 model phones, and I ran across this :
to be honest I have consulted at so many places over the years that I really don't remember most of the companies. Drop me a line at tdennis@DataSourcePro.com with a few more details about the gig. Could be.
The short answer is that you don't.... That isn't entirely true while at
the same time it kind of is, but for the most part you don't configure
the softkeys. You enable or disable them via TCL. Here is the long
answer. Be sure to read the whole thing or e...
Topology: IP Phone > Switches > Microsoft NPS setup to forward 802.1x
proxy to > ISE 2.1 patch 3 Authentication: EAP-TLS using Cisco MIC SANs
Phone Models 802.1X support? 802.1x flavor Addtl Comment EAP-MD5 EAP-TLS
Cisco 3905 Y Y N Cisco 6911 Y Y N Cisco ...
This document describe how DST changes and how time changes are
implemented in DST. Daylight Saving Time (DST) is the practice of
setting the clocks forward 1 hour from standard time during the summer
months, and back again in the fall, in order to make b...