Current problem:

  • 7 desktops installed at client's business
  • 1 dedicated ethernet line for each desktop

The original idea was that each line would run to their VOIP phones and then take advantage of the LAN connection on the phone to connect their desktops.

The VOIP phones have a 10/100 interface and our client is complaining about the lag from the network connections.

My current solutions / thoughts:

  • Small 3 port switch to ensure the desktop has a direct connection off the phone. (Expencive)
  • Install an extra ethernet card in the desktops and run a line from the PC to the phone. Though this would be ideal, they would not be able to use the phone if the computer is shutdown. Is there any way to provide an always on network threw a computer that is shutdown?
  • Current last resort would be to use a hub, but this would not 100% solve the problem. It would only make it somewhat better.

Please let me know if you can come up with a better solution to this issue. Running extra lines and installing new switches would not be cost effective enough but we do have the spare ethernet cards to install.

  • 3
    I doubt the VoIP phones themselves are causing the "lag." Something else is going on. What kind of switch/router are you using, and could you post the configs?
    – Ron Trunk
    Nov 19, 2015 at 13:37
  • Are they experiencing lag inside the network device to device, or connecting out? How much bandwidth is the VoIP or PC actually using that you think separating the wire or rearranging the hops is the main solution? Are the phone links autoneg for 100? How would option 1 solve anything if you still have a single wire going back to the central switch? For that matter, how would option 2?
    – Radhil
    Nov 19, 2015 at 16:08
  • The phones are old and 10/100 only. They are using a cisco small business switch and removing the phone removes the problem.
    – Joe
    Nov 19, 2015 at 20:30
  • My question here is what troubleshooting have you done to find this 'slowness'? Do users complain about it if you bypass their phones temporarily? What equipment do you have? Have you done any tcpdump/wireshark testing?
    – stevieb
    Nov 20, 2015 at 15:14
  • Further... how close are the desks of the users in proximity to each other? Perhaps you could drop in one or two small desktop switches, use a single line to connect to it and split it off to all the phones (and a single PC), and then use the remaining lines that go directly to the wiring closet for the PCs.
    – stevieb
    Nov 20, 2015 at 15:16

2 Answers 2


So assuming you are reasonably certain that the problem is the two-port 10/100 switch built in phones, using a separate three-port switch may work as long as it's a gigabit switch, and the rest of the network upstream is gigabit.

Check the phones to make sure they are not connecting at 10MB. Of course you probably already did that.

Using a hub - there's really no good reason to use a hub here.

Adding a second NIC to the computers will not make the computers act as switches / hubs / repeaters. You could configure them to act as routers, but it would be quite a chore.

VOIP phones with gigabit switches are available, that would work. Or, you could buy headsets for the PCs and use softphones.

  • Budgeting is the bigist problem on this project as I am paying out of pocket. My budget is low to maintain a profit and or break even. I have confirmed that the phones are acting at 10/100. As much as I dispiase the set up they have I'm really straped to the equipment and configuration they have because the owner has made these decisions.(the bigger problem) They do not own the phone system so we can not replace them. Is there a way to get the NIC to continue to route traffic to the phone after shutdown?
    – Joe
    Nov 19, 2015 at 21:37
  • No, I am afraid that when the PC is shut down, both NICs will be dead. Nov 19, 2015 at 21:56
  • I''m skeptical that the phone switch is causing the "lag."
    – Ron Trunk
    Nov 19, 2015 at 22:30
  • @RonTrunk, I would assume in this case that "lag" is used in the user sense (i.e. "things" are slow) rather than the technical sense (i.e. latency is high). Especially since it appears the OP is concerned about the PC performance rather than the VoIP performance.
    – YLearn
    Nov 19, 2015 at 23:05
  • @YLearn I agree, but I wouldn't attribute slowness to the phone.
    – Ron Trunk
    Nov 19, 2015 at 23:06

You should adopt a switch capable of vlan , separate VOIP from data traffic and prioritize voip . no way an hub would solve this type of problems...

  • This has nothing to do with the question. Yes I am aware that using a VLAN would be better but thats not my call. I just need to get the phone connected and the desktop at 10/100/1000full duplex. Completelly un-related.
    – Joe
    Nov 19, 2015 at 20:28
  • 1
    @Joe, I think the poster is saying get a small VLAN capable switch to use at the end user side of the connection. That way you can send a trunk to it with both the VoIP and data VLANs to still keep them separate and treat them differently. Most of your other solutions would involve putting VoIP and data on the same VLAN, which is less than ideal.
    – YLearn
    Nov 19, 2015 at 20:41
  • The installation does not support VLANs. Their installation does not support VLANs nor would that fix the 1 cable problem
    – Joe
    Nov 19, 2015 at 21:28
  • If they aren't separating VoIP and data, then no this will not provide a solution in this case. I will add that industry recommended best practice is to separate VoIP and data, so this would be a solution that falls more in line with best practices.
    – YLearn
    Nov 19, 2015 at 22:53
  • @Joe we're all just guessing here. Help us help you by telling us the type of equipment you have, and perhaps post configurations to see what improvements you could make.
    – Ron Trunk
    Nov 20, 2015 at 0:26

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