Computer behind Cisco IP Phone - Network Issue

[davidsttz]

Dear Community,

we have troubles with some Lenovo notebooks with Realtek PCIe GbE Family Controller, using UltraDock 40AJ.

Those notebooks were plugged behind a Cisco IP Phone CP-8851 or CP-7811.

Always seems to work normal, but when users join a WebEx meeting with video, the network crashes on the notebook.

Also WebEx Meeting crashes and this is annoying.

If you try to ping those computer you get bad response times like following:

10.11.2021 13:27:26-Reply from 10.x.x.x: Bytes=32 Zeit=420ms TTL=127
10.11.2021 13:27:30-Request timed out.
10.11.2021 13:27:35-Request timed out.
10.11.2021 13:27:36-Reply from 10.x.x.x: Bytes=32 Zeit=5ms TTL=127
10.11.2021 13:27:38-Reply from 10.x.x.x: Bytes=32 Zeit=328ms TTL=127
10.11.2021 13:27:42-Request timed out.
10.11.2021 13:27:43-Reply from 10.x.x.x: Bytes=32 Zeit=206ms TTL=127
10.11.2021 13:27:48-Request timed out.
10.11.2021 13:27:49-Reply from 10.x.x.x: Bytes=32 Zeit<1ms TTL=127
10.11.2021 13:27:51-Reply from 10.x.x.x: Bytes=32 Zeit=335ms TTL=127
10.11.2021 13:27:55-Request timed out.
10.11.2021 13:27:57-Reply from 10.x.x.x: Bytes=32 Zeit=1075ms TTL=127
10.11.2021 13:28:01-Request timed out.
10.11.2021 13:28:06-Request timed out.
10.11.2021 13:28:11-Request timed out.
10.11.2021 13:28:16-Request timed out.
10.11.2021 13:28:21-Request timed out.
10.11.2021 13:28:23-Reply from 10.x.x.x: Bytes=32 Zeit=586ms TTL=127
10.11.2021 13:28:24-Reply from 10.x.x.x: Bytes=32 Zeit=896ms TTL=127
10.11.2021 13:28:25-Reply from 10.x.x.x: Bytes=32 Zeit=550ms TTL=127
10.11.2021 13:28:26-Reply from 10.x.x.x: Bytes=32 Zeit=545ms TTL=127
10.11.2021 13:28:26-Reply from 10.x.x.x: Bytes=32 Zeit=101ms TTL=127
10.11.2021 13:28:28-Reply from 10.x.x.x: Bytes=32 Zeit=428ms TTL=127
10.11.2021 13:28:32-Request timed out.
10.11.2021 13:28:37-Request timed out.
10.11.2021 13:28:42-Request timed out.
10.11.2021 13:28:43-Reply from 10.x.x.x: Bytes=32 Zeit<1ms TTL=127
10.11.2021 13:28:48-Request timed out.
10.11.2021 13:28:53-Request timed out.
10.11.2021 13:28:54-Reply from 10.x.x.x: Bytes=32 Zeit=248ms TTL=127

I tried following: Upgrade Docking Station Firmware, Upgrade Realtek Driver from Realtek page, Disabled following Settings on Realtek NIC (Energy-Efficient Ethernet, Auto Disabke Gigabit, Green Ethernet, Power Saving Mode)

If the user removes Cisco IP Phone, everything works OK.

Do somebody know this issue? What else can I check or do to resolve it?

Thx, David

[Nithin Eluvathingal]

Does that happens only when you use Webex Video ? 

What if you connect directly to a network port and run a webex meeting with Video > 

[davidsttz]

Thank you for your reply.

In most cases the user reports it is on Webex Sessions. If you connect the computer directly to a network port and run a Webex Meeting with video, everything is alright. 

I also have users, who report that network is slow. If he browses to internet/intranet pages, it takes long time to load. Also when he saves file on a share. If you ping the computer, you will also get very bad response time like posted above. If the user removes the Cisco IP Phone between switchport and computer everything works fine. But we cannot split IP Phone and computer on all users, because we do not have so much switch ports.

[aflbakker]

Old topic but it seems we are facing similar issues. Did you find any workable solution for this issue ?

[Leo Laohoo]

I strongly recommend updating the Realtek wired/wireless NIC drivers.

[davidsttz · Accepted solution]

Hello, yes we found a solution. we have disabled the "Flow control" feature in the settings of Realtek Network Card. Updating to the latest drivers was not the solution.

[aflbakker]

We also updated drivers to latest (according to Dell , not according to Realtek) and issue persisted.
I'll try tomorrow to disable the flowcontrol and update to latest realtek drivers. 

Let's see what happens. Thanks for the response !