Help me improve voice quality of my voip setup

[Hyrules]

Hi everyone,

I'm an new client of fpl since a couple of weeks now but i'm having some issues with the voice quality. I have an OBI202 as ATA with a new Linksys EA2700 with standard firmware. QOS is enabled and I have configured the mac address of ATA in the QOS priority list as well as the DMZ. I just disabled SIP AGL as it was cutting of my outgoing calls but often callers seems to say that my voice is a little choppy although the caller voice is perfect. I'm with electronic box 30/2 internet package.
To my knowledge it should be enough to support VOIP perfectly. The RTP packet size is set to 20 as recommended. Any input would be appreciated.

thanks.

[dibsmft]

Most importantly, what is your upload speed? While the download speed from an ISP is usually enough for voip the download speed may be inadequate. QOS can sometimes be unreliable especially on a busy network. If the outgoing band with is low then almost any activity on the net work that uses outgoing ban with wil ruin the quality of your phone call.
You really should not be using DMZ as it can be unpredictable. Try removing the ATA from the DMZ, give the ATA a static IP and forward the required ports from the router to the ATA IP with SIPalg off.
Did voip work OK with your old router?

[Hyrules]

The upload speed is 2 Mb/s. The voip did not work properly with the old router.

[Hyrules]

I have disabled the QOS and removed the ATA from the DMZ. The ATA already had a static IP. What are the ports that I need to redirect ? I already have 5060-5061 and 13000 - 13001.

[dibsmft]

My upload speed is 0.6 mbits/sec so you should have no problem.

Settings
SIpAlg Off
Check that the ATA actually gets the fixed IP.
Try ports 5061 and 5062 UDP for Line 1 and 2 SIP respectively ... set those as the internal ports on the ATA. The external port should be set as 5060 UDP in the ATA but do not forward it.
I would us ports 8000 - 8010 UDP for the RTP ports forward and record in the ATA set up. This would be the minimum ports for me but on my set up with up to 6 voip lines minimal is enough and two voip ports. (If you really like 1300 -1301 you can use it (it should make no difference for standard SIP) but make it 13000 - 13020 UDP).
Power down the router and ATA, wait 5 min and the power up the router and then the ATA. Test.

[Hyrules]

I have set the fixed ip directly on the ATA not in the router. I have only 1 line. I noticed that there seems to be 2 occasions where the line is choppy. If someone is on the internet and when someone speaks loudly in the phone. Unfortunately we are a natural loud speaking people. I also noticed that my server is somehow hogging the router. Unplugging it lower to first ping to nearly 0 or 1 ms.

[dibsmft]

I have set the fixed ip directly on the ATA not in the router. I have only 1 line. I noticed that there seems to be 2 occasions where the line is choppy. If someone is on the internet and when someone speaks loudly in the phone. Unfortunately we are a natural loud speaking people. I also noticed that my server is somehow hogging the router. Unplugging it lower to first ping to nearly 0 or 1 ms.

It looks a bit like your QOS was not working or you upload is really <<3 mbits/sec. Your ATA should have some voice level controls so you could lower the outgoing audio volume a bit. Are you using a phone handset, open mic and speakers(unlikely)...? If the out audio hears the in audio in some way then you will probably get clipping as the AVC will activate ... the lower the audio volume that you use the better. Your a running a server? That will not help either. I thought that the OB1202 had 2 lines and a router so you could perhaps run the server from the ATA router which should allow the ATA to get higher priority.

[Hyrules]

Yes the ATA can get 2 lines but i'm using only one. I'm using a handset. Wireless one Panasonic 5.8 Ghz. I'm wondering if the problem is not caused by the wireless phone. I've read somewhere people having trouble with wireless phones that were not DECT 6.0. I see your point about the ATA and the Server but the problem is that server is a mediaserver with a Gigabit NIC and the ATA is not gigabit. Actually the server is not really connected from the external. Every 15 minutes it upload weather data for a minute or 2 and sometime when someone connect to my website the server fetch the weather data in a txt format which is really small.

Here is the speedtest of my line.

[dibsmft]

Handset should be OK My cordless phone is not Dect 6, in fact I think it is 2.4 MHz. If your base station is very close to the router it might give trouble but it should be OK. You really should not be having problems as your speed is way more than mine which is 7 Mbits/sec down and 0.6 Mbits/sec up. I used to have about 1 Mbits/sec down and 0.6 Mbits/sec up and ran a server on that network (all Linux) which also did the duties of a router with no problems other than being slowish by modern standards but voip was OK.

[Hyrules]

the phone base is at the other side of the house. The router is literally in the middle. That would be something like 20 feets. There must be something on my network hogging the power. Should the QOS be enable in my case or is it not necessary since I have more bandwidth ?

[Bloodsong]

Simple troubleshooting step number 1) Remove the router from the equation, hook OBI straight to your modem (Is it a modem only, or set-up as modem only?)

Test voice quality now.

With the ATA as the only thing using the network you should have the best possible audio quality allowed by your connection, provider, and phones.
Modems do not do QOS and so cannot have broken QOS, and the router is out of the way.
There is no conflicting traffic so QOS is unnecessary.
There are not additional hops inside your network so port-forwarding is unnecessary. (assuming your modem acts as a modem only.)

Assuming voice quality improves use that quality as a target mark for all other troubleshooting, but first start by proving that quality can improve.

EDIT:

RE: QOS, Quality of Service set-ups primary purpose is to designate a priority sequence to packets, not a priority on the amount of bandwidth necessarily. This is because certain services are more jitter sensitive (Such as VoIP) and require the highest possible priority entering and exiting the network, and are not happy to simply wait their turn in queue. It's like being handed a VIP pass to the opening night at a hot-new night club.

So whether you have 0.512 or 300Mbps bandwidth available, it doesn't mean squat if the network is busy with other traffic clogging up the queue.

[Hyrules]

the modem is a Thompson DCM475. It's a real modem. No other job than that. I will try to do so.

Here is a ping and Jitter test as you can see the line does not seem to be the culprit here :

[dibsmft]

With the speed that you have it still surprises me that you have problems. When compared to my internet your calls should be near perfect. Something must be using band width that you have not accounted for ... perhaps someone is using a bit torrent or a webcam uploading pictures on the quiet. Have you tried the OB1202 with other voip services and, if so, how is the quality there?

[Hyrules]

No i havn't tried with another voip service. My actual phone number was ported to fpl and i'm using it as primary phone line. I also find it strange that I'm having problem with that quality of line. Something inside my network must be like you said hogging bandwidth. I have 3 computers on that lan and 1 printer. 2 are normal computers. Mine and my parent's. They dont know how to used bit torrent or upload stuff. The last computer is a mediacenter and is rarely connected to the internet sometimes to upload weather data which is really small. I have check windows resource monitor on their computer to see the network activity level and when they are not on the internet it's flat 0 kb/s. Right now my server is also at 0 and not often going to 1 kbps. Mine is also at 0...

[dibsmft]

I have never tested any of the OB1 series so I don't know what problems they present.

Sent you a pm.

[Hyrules]

After testing today i find the line quality has improved alot since I've disabled what I tought was causing the problem. I think I have found what was taxing my router. I had almost no chopping at all. In a 2 minutes conversation the line may have twitched twice. but you have to be looking for glitches in the voip line. I'm also wondering if I still need QOS as I'm not planning on doing massive upload. ( no torrent but some usenet which does not upload). I'm also using OBItalk portal instead of the direct interface to configure my obi. That way i'm assured of the latest firmware. I went from firmware 3180M which i tought was the latest to 3397 .

[dibsmft]

What was the problem caused by? It might help others to know.
With the bandwidth you have I would not expect you to need QOS based on what you say you use the service for.

[Hyrules]

Right... i will disable it to see if it affect quality. I doubt the problem will help anyone since it is really specialized and something people rarely do. I have a weather station here. It was offered to me by a company that monitor water level in rivers on condition that I upload the data to their server every 15 minutes that was not the problem I'm just to putting things in context. I have another software named Cumulus that was fetching the data in real time from the weather station over the network thus causing my router to be taxed to the point where it would slow down just enough for my VOIP setup to become choppy but not enough for me to see while browsing or doing other tasks. While it was running i was seeing the LED on my gig switch always flickering thus telling me that something on my server was constantly using the network.

[Bloodsong]

Ah, I looked into some of those weather station set-up for home not long ago.
If you find that you have additional issue and would like some help with QOS let me know.

Most QOS set-ups do allow you to load-balance your network internally rather than as it enters the WAN. Which could be helpful depending on how much the media server is uses.

[Hyrules]

thanks. The mediaserver is rarely used during the day only at night. But this morning I had a call from my aunt and she told me that it was still choppy. I'm starting to wonder what could be doing that. Many people i`ve talked to notice no difference when I speak. Although I didnt try to call home with a cellphone and see if it was still choppy. At the moment she called I was checking a usenet file but with 30 mb / 3 mb i doubt that i could be the line. There still must be something in my network causing that. I know I fixed a problem of noise on the line by plugging the phone directly in the ATA.

[Bloodsong]

In-house wiring can be very susceptible to environmental factors as it ages. *nod*

It could be the usenet file's fault, as you were probably receiving 2-6MB/s it would monopolize the sequence of traffic on the router, this is what causes jitter and choppiness.

my personal QOS set-up has SIP and RTP given top priority access to the network (SIP is set to "express" which is a priority of 20 and RTP is premium a priority of 10)
This means any time my router detects one of the systems in my house to be using SIP or RTP there is a level of priority applied. (Note: RTP can also help with video streaming services.)

I also have a MAC based priority applied to the phone of "Express" and I believe my Wii (For netflix purposes)

Then finally I have a port based priorities set as well. Ports 1 and 2 have 50 and 20 MB dedicated on the LAN + priority of Standard(30) (Express(20) sometimes when I'm less worried about voice quality, I've never had a problem with either setting), the phone's port is given 256KB dedicated LAN + priority of "premium"(10) and my printer has a mere 2MB of LAN priority "bulk" (40).

The QOS tagging has a cascading effect causing all of my traffic at some level in the LAN to be prioritized with an assurance that the phone will always have enough bandwidth for two-way voice, even with a high pack-rate selected on ULAW, and will be sequenced first in-line making computers and other services wait in line.

I added the MAC of the Wii because there is no port or bandwidth settings for WAN connections and didn't want it to be relegated "end of the line" as it then gains priority for netflix both under MAC and under RTP designations I can be assured that the only thing with higher precedence than the netflix (our own television) is the phone.

With this set-up I can be downloading multiple games with 1.7-2.4MB/s download streams and still never interrupt my call quality.

[Hyrules]

thanks for the info. I have reactivated the QOS on my network. This should help with the internal network congestion if there is. The QOS in the linksys router is pretty much simple. there is 3 level of priority and I can setup QOS only on program, voice device, mac or games. I have configured the mac priority to my ATA to the highest priority. there is no port priority on the standard firmware and DD-WRT is a WIP for that router.

[bridonca]

I think your router with the defective firmware is your problem. You fix that, and you will not have to deal with QOS. You cannot fix QOS issues with bad firmware, because the bad firmware is running the QOS. Time for another router that is up to the task, since you cannot upgrade to DD-WRT.

Here is a link to a cheap DD-WRT friendly router, http://www.futureshop.ca/en-CA/product/ ... 75bb6een02

[Hyrules]

Actually I changed the router again... I bought a non friendly DD-WRT although it's rated the best router at http://www.smallnetbuilder.com/ it's the RT-N56U from Asus. It has hardware NAT and QOS.

[Bloodsong]

Nothing intrinsically wrong with routers that can't use DD-WRT, mostly it comes down to the hardware and the programming of the firmware. DD-WRT is just a safe way out of a bad situation