Cisco 7811 IP Phone

[kochjason]

Can a Cisco 7811 IP Phone use a port running a 1000mbs connection?  Can this cause network stability issues with network performance on a computer that is using the PC Port?

[b.winter]

Just check the datasheet of the phone type, to see which port speeds the built-in switch of the phone supports. Google is your friend.

Why should it cause network stability issues?

[kochjason]

I did, and it showed 10/100mbs port.  The phone works on the 1000mbs port, but the computer is experiencing dropped intermittent network connection when plugged into the PC Port on the phone.  If I disconnect the phone, and run the ethernet straight into the computer no issues.  Trying to determine if the 1000mbs connection to the phone is causing an issue.

[b.winter]

If you have configured the port on the switch correctly, then it should regulate itself to 100mbit, cause the phone can not support more.

So, if you have problems, then I would check the port settings on the switch.

Possible causes could be:

CDP disabled (phone is correctly recognized by the switch, leading to possible multiple further problems)

VLAN config is incorrect (phone "jumps" between voice vlan and access vlan)

speed and duplex negotiation fails, if phone is in between

[kochjason]

Thank you.  I was leaning towards a negotiation issue.  Can I just set the phone to 100 full and leave auto negotation off?  Would that correct a possible issue?

[b.winter]

Yes, that could be a possible first step, to check if it gets better.

[kochjason]

Thank you very much for your thoughtful replies.

[b.winter]

No problem, that's what the forum is here for ':-)'

I'd surely be glad, to get an "accepted solution" after the problem could be solved then.

[Leo Laohoo]

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@kochjason wrote:

I did, and it showed 10/100mbs port.  The phone works on the 1000mbs port

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What is the model of the switch?

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@kochjason wrote:

the computer is experiencing dropped intermittent network connection when plugged into the PC Port on the phone

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The cable from the phone to the PC is faulty?

[kochjason]

In this situation would I set to 100 half or 100 full?

[b.winter]

100 full

Always full.

[kochjason]

Thanks.