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VoIP phones losing connection randomly for a brief moment

liamelder
Level 1
Level 1

So back story here. Just installed two SG200-26 switches (replacing a unmanaged switch) which are connected together via a trunk.

However my SPA921 VoIP phones randomly have the Mic light flash red (which indicates loss of network connection). It happens for a literally a second and reconnects. When pinging the phone you can see a single ping not getting a reply. It also appears randomly on what seems to be most of the phones but not all at the same time, some may be fine while maybe one or two have the issue. It may have it continuously loosing connection for a brief moments for a while then likewise it my be fine for a while or the rest of the day.

Im looking for some ideas for troubleshooting. So far I tried changing the phone ports to static 10M half duplex instead of autosensing and this seems to not have resolved the issue.

Your help is appreciated.

Thanks

Liam

6 Replies 6

Tom Watts
VIP Alumni
VIP Alumni

Hi Liam, it may be an idea to disable the energy efficient ethernet settings.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/

I have fully turned off the Green Ethernet on both switches but still have the issue

liamelder
Level 1
Level 1

This was one of the ports I was having a problem with, It went down and up becuase I had done a Admin Shutdown on it. However what is it refering to by 'Aggregated'?

21474831582013-Aug-28 17:18:32Informational%LINK-I-Up:  gi15, aggregated (3)     
21474831592013-Aug-28 17:18:20Warning%LINK-W-Down:  gi15, aggregated (3)   

Also brief loss of connection happens even when not going through the trunk

Hey Folks,

Still looking for help with this one. I have 'played' about with every function (I think), or well turned a lot of stuff off (auto port speed, auto mdix, green ethernet, stp and other stuff). I have tried this on both my new switches.

I have tried factory resetting the switches and setting them stand alone with only the phones and my laptop plugged in and still have the intermittent Flashing Microphone light(breif connection loss). The fact its happening on both switches rules out hardware (not that that was likely).

Is there something I am missing, or something I need to turn on?

Im going crazy with this one.

Thanks

Liam

Hi only other thing I may think of is either spanning tree (disable it or manually enable port fast to see what happens) or the switch macros, may try to disable them to see what happens.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/

I tried turning off Spanning tree and Smart port to no avail