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Unexpected Connectivity Loss behind IP Phone 8945


We are experiencing numerous but hazardous PC network outages when they are connected behind a Cisco 8945 phone with Auto network settings.

We are linked like this :

Catalyst 2960S  --------  IP Phone 8945  --------  PC


Settings are Auto/Auto on Catalyst, IP Phone 8945 and PC Network card. All equipments go to 1000 Full.

No errors at all on catalyst counters, status on IP Phone 8945 shows Port 1 and Port 2 to 1000 Full.

But sometimes, whether a user is logged onto the computer or not, user working or session locked, PC looses connectivity. No way to solve it unless a reboot is initiated. PC port on 8945 works, only the PC network card is oos.

Issue does not appear when forcing all equipments to 100 Full.

Seems we do not have this issue when using 9951 (Auto settings , then Gigabit).

Issue does not appear if we connect only computer and catalyst with Auto settings.

We have Intel 82578DM network cards with the latest certified HP Drivers, running on Win7 SP1.

8945 are running latest sccp 9-3-2-11 firmware, but with previous firmwares we'were already experiencing this problem.

Does anybody has ever experienced or heard something about this problem ?




Does someone has a successful installation of 8945 phones connected to computers using automode everywhere (then ports going to Gigabit) , without any problems ?



Did you ever find the problem here?  We have different phone models, but since adding them to the network, we're having some intermittent issues.


Happens also with 9951 model finally.

Seems the problem is related to the NIC driver with some PC models. Case is on the HP side but it's slow...


srichardson, can you tell me more about the PC model and the NIC card / driver where you experienced your problems ?



Did you ever get a resolution for this?  I have the same issue with HP thin clients behind 8945's.  They work fine for a while but then we have to reboot the phone to get them to reconnect.  I tried setting one of them to 100 full on the phone and the client to see if it fixes the issue.


What kind of switch do you have at the end and what settings do you use (i.e. auto Giga or 100 Full fix)

We have 2960S's with auto auto set on the ports.


Could be linked to this catalyst model and HP NIC. (I said "could")

We set the whole path to auto mode, with auto synchronisation enabled on IP Phone in order for the PC side not to run to Giga, and set the catalyst side to auto 100 maximum.

Seems the problem is solved by this workaround. Not 100% sure because we have only a few weeks of statistics.

We loose Giga speed but the target is to avoid disconnections.


Dustinn3 , what is the brand of the NIC into the HP thin client ? Intel 82578DM or something similar ?

Hello Dustinn3, any update on the NIC model so we can correlate this issue with some kind of hardware and driver ?

Thanks for feedback.

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