How to configure QOS on Linksys WRTP54G for VoIP?

Posts: 2 · New Forum Member Joined: Jul 19, 2005 Posts: 2

I've read a number of posts on this forum that say how important the QOS feature is to quality Voip phone service. On my WRTP54G router, I see there is a QOS tab under "Applications & Gaming", but there doesn't seem to be any thing pre-configured for Voip to give it priority. It looks like you would need to configure it manually based on the TCP ports used by Voip.

Does any have recommendations on how this should be configured or is this something handled by the firmware?

Posts: 1715 · Posted: Thu Jul 21, 2005 11:11 am Post subject:

Is there a way to configure QoS by port # (as in LAN port #) on that router? I haven't popped the cover on any of these yet, but I'm willing to bet the phone adapter & router are separate circuits and the PA's probably just hooked into a port on the built-in switch.

Posts: 2 · New Forum Member Joined: Jul 19, 2005 Posts: 2

I haven't seen any way to configure QOS by Physical port, just TCP port. I agree with you that the phone adapters are probably separate devices just connected internally. That's why I thought the QOS for those devices might be configured in the firmware. I was hoping somebody on the forum might know for sure.

Posts: 7 · New Forum Member Joined: Jul 15, 2005 Posts: 7

The default Voip port is 5060. Configuring that port to high priority gave me a small upgrade in Voip quality (according to some test, I myself cannot tell the difference).

Posts: 2 · New Forum Member Joined: Jul 27, 2005 Posts: 2

bl13 wrote:

The default Voip port is 5060. Configuring that port to high priority gave me a small upgrade in Voip quality (according to some test, I myself cannot tell the difference).

Slightly incorrect. Port 5060 is used for SIP signalling alone, not for the RTP media streams, and therefore no amount of tweaking QoS settings for this port should have a noticable bearing on your voice quality once a call has been established. No user configuration needs to be done for Voip traffic (both RTP & SIP). This should be internally prioritized by the firmware itself.

Posts: 2 · New Forum Member Joined: Jul 28, 2005 Posts: 2

Ok

So in regards to QoS, what port do you recommend, because I know I get jitter when I am surfing or yanking big files down from the net.

What do you suggest to reduce jitter?

Suggestion 1
Disable QoS use Auto, will that prioritize Voip?

Suggestion 2
Does the device share a physical ethernet port? I want to use a port that is not being shared with the Voip any port suggestion? I assume port 1 is the shared port? So if I want to use port base QoS, for the Voip do I plug my external switch into port 2 that house my internal network and do the following.
Priority Low
Flow Control Enabled
Ingress rate disable Perhaps enable and select 1m, but I really do not want to fool with this since this is really based on the downward stream which can fluctuate from 3m to 512k downstream to the device.

What do you think?

Posts: 2 · New Forum Member Joined: Jul 27, 2005 Posts: 2

gggraham wrote:

Ok

So in regards to QoS, what port do you recommend, because I know I get jitter when I am surfing or yanking big files down from the net.

What do you suggest to reduce jitter?

Suggestion 1
Disable QoS use Auto, will that prioritize Voip?

Suggestion 2
Does the device share a physical ethernet port? I want to use a port that is not being shared with the Voip any port suggestion? I assume port 1 is the shared port? So if I want to use port base QoS, for the Voip do I plug my external switch into port 2 that house my internal network and do the following.
Priority Low
Flow Control Enabled
Ingress rate disable Perhaps enable and select 1m, but I really do not want to fool with this since this is really based on the downward stream which can fluctuate from 3m to 512k downstream to the device.

What do you think?

I do not think the jitter you notice is possibly improved/affected by the 5060 rule you have configured. Like I said before, when you introduce traffic (uploads/downloads and such), the 5060 rule cannot help because that is simply not the port used for RTP.

The behaviour and performance of the device (as far as voice goes) should be irrespective of your QoS setup, and definitely irrespective of the LAN side layout/configuration

Posts: 2 · New Forum Member Joined: Jul 28, 2005 Posts: 2

I am not the same person who tried the 5060 IP port range..... I was trying to get clarification because I too am experiencing some Voip degradation.

How can I improve performance and what else has anyone tried or recommended?

Both suggestions are valid, one is stated in the manual, but does not give any reason for it, and the the other would be perfered. The reason being is:

It addresses the download and upload stream and to correct jitter you need to do the following.

A. Ensure that QoS is assign to the correct physical port or per IP port specific address range. Currently I have not seen what port Vonage uses, though I am tempted to set up a sniffer.....

And this may be infered in the manual.

B. Bandwidth or vlan to reduce traffic

Hence option 2. would be perfered with the QoS, per physical port not per IP port on the same vlan router, and I want to put QoS on the entire physical port that my back office is using, to ensure that the router handles Voip internal and then proiritize traffic as low per physical port. That is why I asked what physical port was being used or shared with the backplane of the router.

I am using a wrt54gp2

Posts: 646 · Posted: Thu Jul 28, 2005 1:40 pm Post subject:

Can someone post a screenshot of the WRTP54G's QoS page? I've never seen it.

Posts: 533 · Posted: Thu Jul 28, 2005 8:40 pm Post subject:

Vonage uses SIP and RTP Audio, both are UDP. Someone mentioned something about TCP in this thread, so I wanted to clear that up.

How you implement is going to depend on your router's capabilities, but unless you are doing massive file transfers on your home network, I wouldn't apply QoS to anything but egress traffic out to your ISP. One thing to remember about QoS is that it does not take effect until there is congestion, which you may never have on your own LAN, but most certainly will at your egress. Your own LAN should have plenty of bandwidth, hence very little congestion.

If your router can do it, give the RTP audio protocol (this is for your conversations) a guaranteed 90Kbps (if you're at the highest quality level), and give SIP (call signalling) maybe around 15Kbps. If your router can't do this by protocol, try it by UDP port. Vonage says they use 5060 and 5061 for SIP (I've only seen the standard 5060 used though) and 10000-20000 for RTP audio. Since they use such a wide range of ports for RTP, you can see it's better to do that by the protocol. Keep in mind these are destination ports, not source.

There isn't anything you can do about ingress QoS (Internet inbound to you) until it hits your router, so don't bother with it.

HTH

gggraham wrote:

I am not the same person who tried the 5060 IP port range..... I was trying to get clarification because I too am experiencing some Voip degradation.

How can I improve performance and what else has anyone tried or recommended?

Both suggestions are valid, one is stated in the manual, but does not give any reason for it, and the the other would be perfered. The reason being is:

It addresses the download and upload stream and to correct jitter you need to do the following.

A. Ensure that QoS is assign to the correct physical port or per IP port specific address range. Currently I have not seen what port Vonage uses, though I am tempted to set up a sniffer.....

And this may be infered in the manual.

B. Bandwidth or vlan to reduce traffic

Hence option 2. would be perfered with the QoS, per physical port not per IP port on the same vlan router, and I want to put QoS on the entire physical port that my back office is using, to ensure that the router handles Voip internal and then proiritize traffic as low per physical port. That is why I asked what physical port was being used or shared with the backplane of the router.

I am using a wrt54gp2