tried dmz, disabling spi firewall..intermittent audio

[patkins99]

Just got the viatalk service, and we are testing this out prior to porting over our landline. I have a linksys WRT54GX4. With the SPI firewall turned on, we were getting waves of audio. I turned it off and the sound was good. I called tech support and they suggested putting the voip device in the dmz, which I did. I turned the spi firewall setting on again and the intermittent audio returned. So, turned it off but kept the dmz on. I'd like to keep the firewall on if I can. I ran "shields up" with the firewall off, and it detected none of my ports, but was able to "ping" me.
Any other ideas? Can it put the voip box outside my router and run the daisychain to the router?

[Brian188]

It is odd that you would have problems with the adapter in the DMZ and the firewall up, as that is what the DMZ does, it bypasses the firewall. Just to clarify, you had the Firewall turned on and the PAP2 in the DMZ, correct? And you were having audio problems at that point.

Try running two tests on www.testmyvoip.com The first test with your computer plugged into the router, and the second with your computer plugged directly into the modem. If there are big differences it will help you nail down if this is a router issue, modem issue, or ISP problem.

You can't set the adapter outside of the router, because there is only 1 ethernet port on the PAP2, so you wouldn't be able to connect the router or a computer.

[patkins99]

Thanks Brian,
Yes, I had the adapter in the dmz and the firewall turned on and the audio problems. I turned in a ticket at that point to tech support, and they suggested port forwarding in addition to the PAP2 in the dmz, specifically "SIP ports 5060-6000 and RTP ports 10,000 to 20,000.". I've never done this before, so not entirely sure what this means.....

[Brian188]

I'm a little doubtful that port forwarding will help you, but it can't hurt. Go here if you're not sure how to do it.
http://www.portforward.com/english/applications/port_forwarding/Viatalk/Viatalkindex.htm

Find your router on that page and follow the step-by-step instructions.

[chas3]

Let's further consider the merits of turning off SPI. It worked for patkins99. I found the following at http://www.sipura.com/Documents/faq/Section_1.html which is a linksys/cisco company.
They are saying to turn off SPI.....

"5: I want to buy, but I have a firewall. Will the SPA work?
A: If you have a firewall, make sure you are not blocking the UDP PORT 5060,5061 and port for UDP packets in the range of 16384-16482.
You will also need to disable "SPI" if there is such function in your firewall.
Depending on the SIP server that you are going to register to, If it supports NAT, then you can use "Outbound Proxy" configuration of the SPA to connect to it. Otherwise, SPA also supports STUN protocol. (see "SIP" tab config from web GUI) Please note that STUN will not work if you have a symmetric NAT. If you enable the debug through syslog, and set "STUN test" to yes, SPA will print information about whether or not you have a symmetric NAT. "

Any thoughts?

[Heat305]

Can someone please give me some advice of what might be causing this on my VT line. I currently have TWC digital phone service, but testing out VT at the moment. When downloading files from the internet I don't get the same audio issues from my TWC line. Some forums on dslreports claims that TWC Digital Phone does not touch the regular bandwidth for my Road Runner. I don't have any router connected. My Linksys SPA-3102 is connected directly to my cable modem from Road Runner. I tested my speeds on speakeasy.net and my speeds were fine. MY connection setup is as follows: Road Runner Cable Modem>Linksys SPA-3102>PC. My PC is the only other device connected to the internet besides the Linksys SPA-3102. I currently get (5 Mbps down X 384 Kbps up) from Road Runner. This is what they advertise on their website. http://www.timewarnercable.com/elpaso/products/internet/roadrunner.html

I have attached a screenshot of my Qos setting in my Linksys SPA-3102. Any feedback is grately appreciated. Thanks in advance.

[Brian188]

Hi Heat305, My first question is what are the problems are you are having? Broken audio? no audio, dropped calls, popping, static, etc. You only said you don't get the same audio issues on your TWC line. What issues?

I'll also say this, testing up/down speeds does not tell you much. All that really tells you is you CAN run a VoIP call, not what the quality may be like. Try running a test on www.testmyvoip.com to Boston. After the test completes click the "see detailed results" button, and look for latency, packet loss, packet discards, and jitter. All of these things will effect call quality far more than up or down speeds.

You may also want to run a trace route (tracert from a cmd prompt) to houston-1.vtnoc.net (or whichever server you are on) and see if anything times out, or if you have very high times on any of the hops. Times are measured in milliseconds (ms).

Post what you find out.

[patkins99]

Hi all,
as I was the one that began this thread, thought I'd share the latest. thanks for the advice...I did put the PAP2 in the dmz. (I want to keep DCHP going in the router, so not sure how long the device will keep that IP address). I would not mind giving my PAP a static address, but don't want to configure all of our home computers/work computers to static. Anyway, also did port forwarding with the ports that VT gave me. Not sure if i did that right, (what is UDP, TCIP anyway or "both" anyway). In any event, after doing all that, if my SIP firewall setting was on, I got the audio drop outs and the test on test my voip was terrible. If I turned SIP firewall off, got great speed results and the qaulity was great. So, it appears that SIP firewal will stay off and I'll have to contend with the NAT firewall built in to the router. I have a MAC and Windows network here at home. So, that's my experience so far..

[Heat305]

Hi Heat305, My first question is what are the problems are you are having? Broken audio? no audio, dropped calls, popping, static, etc. You only said you don't get the same audio issues on your TWC line. What issues?

I'll also say this, testing up/down speeds does not tell you much. All that really tells you is you CAN run a VoIP call, not what the quality may be like. Try running a test on www.testmyvoip.com to Boston. After the test completes click the "see detailed results" button, and look for latency, packet loss, packet discards, and jitter. All of these things will effect call quality far more than up or down speeds.

You may also want to run a trace route (tracert from a cmd prompt) to houston-1.vtnoc.net (or whichever server you are on) and see if anything times out, or if you have very high times on any of the hops. Times are measured in milliseconds (ms).

Post what you find out.

Yes I am getting "Broken Audio" or "Choppy Audio", whichever you prefer. I haven't had any dropped calls thank god. when I download large files. I don't experience the same with my TWC line when downloading the same files. I ran the test and posted them. I did the online test once and the tracert once, hope it was enough to tell what's going on. Thanks for the assistance Brian188 and I await your feedback.

PS: I am still waiting feedback on the "International Block" feature from my other posting. Can you please read my last posting over there. Ty. http://forums.hostrocket.com/showthread.php?t=20466

[Brian188]

Your scores are actually pretty good**. I assume that your were not downloading/uploading anything while running this test.

** Pretty good meaning not very good, but at the same time not bad.

Here's the only issue I see in your results: Packet discards is at 2%. And this is on a relatively inactive connection. So when you are downloading or uploading large files this number probably goes up considerably. this would be what causes your 'choppy' audio. Here's how VoIP works in a nutshell in case you're unsure.

Your voice is broken up in to packets and distributed through the internet, those packets are sent in order, if a packet doesn't make it (packet loss) to the other side (other caller) or if the packet takes to long to get to the other side it gets there out of order and it is then discarded (packet discards) So here is a really simple example. If you say "hello my name is John Smith and today is Monday June 10 2009." lets say this is broken into the following packets 1.Hel 2.lo 3.m 4.yna 5.meis 6.Joh 7.nSmith 8.andt 9.odayis 10.Mo 11.dayJun 12.e10200 13.9. Now let's say packet 2, and 8 are lost, and packets 4, 6, and 10 are discarded. You'd be left with "Hel m meis nSmith odayis dayJun e10200 9." Doesn't make much sense right? But that is exactly what you are (or your caller is hearing).

So that explains the problem but not how to fix it right? Unfortunately, packet loss and discards are almost always an ISP or modem problem (or router, but you're not using one.) Since you are not having issues with your TWC line I doubt it is your modem. It doesn't happen on your TWC line because that service is provided by TW, so they have optimised their service (ISP service) to work best with THEIR digital voice service.

There are couple of suggestions I would give you:

The First (and free): Take your modem back to your cable company and exchange it for a new one. This will eliminate the possibly that this is caused by your modem. One note: this only works IF you are renting your modem from TW. If not your stuck with the one you got unless you want to buy a new one (NOT recommended at this point.) There is most likely a TW office close by that you can stop by and turn in your old modem for a new one (I do this at Comcast every few months) no need to schedule an appointment for a tech to come out... unless... see option 3 below.

The second (may be some cost): Check all your connections and cables. Be sure the coaxial cable is connected tightly to the wall and the modem, eliminate as many splitters as possible! That is key - eliminate as many splitters as possible! Check for where the cable comes into your house all the way through the house for splitters, and ensure there are no kinks in your coaxial cable, if there are replace the cable.

The Third (still free): Complain to your ISP, and insist they correct the packet loss/discards. They may need to send a tech to your house to check things out.

Fourth (costs): Add a router to your configuration preferably one with good QoS. You see, VoIP adapters are inherently bad for acting as routers, and this is essentially what you are doing when connecting your PC to it. By adding a router you take the load off the adapter of providing an internet connection to your PC. The less work your adapter has to do the better.

[Heat305]

Your scores are actually pretty good**. I assume that your were not downloading/uploading anything while running this test.

** Pretty good meaning not very good, but at the same time not bad.

Here's the only issue I see in your results: Packet discards is at 2%. And this is on a relatively inactive connection. So when you are downloading or uploading large files this number probably goes up considerably. this would be what causes your 'choppy' audio. Here's how VoIP works in a nutshell in case you're unsure.

Your voice is broken up in to packets and distributed through the internet, those packets are sent in order, if a packet doesn't make it (packet loss) to the other side (other caller) or if the packet takes to long to get to the other side it gets there out of order and it is then discarded (packet discards) So here is a really simple example. If you say "hello my name is John Smith and today is Monday June 10 2009." lets say this is broken into the following packets 1.Hel 2.lo 3.m 4.yna 5.meis 6.Joh 7.nSmith 8.andt 9.odayis 10.Mo 11.dayJun 12.e10200 13.9. Now let's say packet 2, and 8 are lost, and packets 4, 6, and 10 are discarded. You'd be left with "Hel m meis nSmith odayis dayJun e10200 9." Doesn't make much sense right? But that is exactly what you are (or your caller is hearing).

So that explains the problem but not how to fix it right? Unfortunately, packet loss and discards are almost always an ISP or modem problem (or router, but you're not using one.) Since you are not having issues with your TWC line I doubt it is your modem. It doesn't happen on your TWC line because that service is provided by TW, so they have optimised their service (ISP service) to work best with THEIR digital voice service.

There are couple of suggestions I would give you:

The First (and free): Take your modem back to your cable company and exchange it for a new one. This will eliminate the possibly that this is caused by your modem. One note: this only works IF you are renting your modem from TW. If not your stuck with the one you got unless you want to buy a new one (NOT recommended at this point.) There is most likely a TW office close by that you can stop by and turn in your old modem for a new one (I do this at Comcast every few months) no need to schedule an appointment for a tech to come out... unless... see option 3 below.

The second (may be some cost): Check all your connections and cables. Be sure the coaxial cable is connected tightly to the wall and the modem, eliminate as many splitters as possible! That is key - eliminate as many splitters as possible! Check for where the cable comes into your house all the way through the house for splitters, and ensure there are no kinks in your coaxial cable, if there are replace the cable.

The Third (still free): Complain to your ISP, and insist they correct the packet loss/discards. They may need to send a tech to your house to check things out.

Fourth (costs): Add a router to your configuration preferably one with good QoS. You see, VoIP adapters are inherently bad for acting as routers, and this is essentially what you are doing when connecting your PC to it. By adding a router you take the load off the adapter of providing an internet connection to your PC. The less work your adapter has to do the better.

Thanks Brian188 for all the useful info, yes I was not downloading anything when I ran the tests. Will try and see if all my cable connections are tight and secure. I don't have cable from TWC, so I took off the "Splitter" that was located outside my house that came from the pole and replaced it with one of those connectors that just act as a bridge so to say, so it looks like it's one straight connection with no break in the line don't know the name for that connector sorry. That's about the only place it in the cable that was split. Now about the "Modem", I have tried several times in the past to get one switched out with TWC and they have sent me back home saying that a "Tech" needs to come out and verify that my "Modem" is acting up. They say in the past customers would come in and exchange it for another one while the exchanged one had no defects. They are so picky down here and since they are the only cable provider over here they act like this. I so want to get rid of them but my only other option is ATT. I am not gonna get an additional phone line just to get internet at my home. There are some providers that offer "Naked DSL" but it's way too expensive. TWC controls the market over here and I think they would raise all hell if another provider came in. They are the only cable company still providing low residential speeds when Comcast, Cox, and others are offering more at no additional charge. I will however give it a try by walking in with my modem and see what they say, and this is what I have done in the past, just show up with the modem in my hand and ask for an exchange and they have told me I need to make an appointment to have a tech check it out. I was gonna get rid of the modem anyhow once I cut out the Digital Phone service. The modem for the phone is different from the one that's just for Road Runner alone, but VT has not replied to me since my last posting about the "International Block" feature. Or I would of already had my number ported over with them. Don't know what's taking them this long to give me a definite answer. Do you have the feature enabled also on your line with VT? Have you tried making an international call to see if it's really blocked? In my other post I had asked one of you guys as a favor to try it and see what happens. Would like to see if the "Status" of the call shows "Answered" with the feature enabled. I really do want to switch over, but I am getting a little disappointed waiting this long. When I call support they say to submit a ticket. I am half way through the month of trying out VT to see if I wanted to switch. I might consider trying out another provider that offers "BYOD" also. Will wait and give VT the benefit of the doubt. Will keep you posted. Thanks again.

[chas3]

You can ask VT to change SIP ports from 5060 to a different like 5080. Some forums are reporting that some cable providers are messing with port 5060 to prevent voip that is not their own.

[Heat305]

What a coincidence this morning I decided to give the testmyvoip another whirl and it gave me a failed message stating that SIP was being blocked. I had never seen that message before. I tried to run another test and now it's working fine. I can't seem to re-create the failed message the first time I ran it this morning. Can you provide me the link to that posting in here and exactly what's the SIP port for and why do some cable companies block it and how do you know which one to use? Will this help my "Choppy Audio" when downloading files? Do you think this is how TWC prioritize their Digital Phone Service so downloads don't interfere with my calls on their line? Also look what I found in my Linksys SPA-3102 settings for SIP. Thanks in advance.

[Reiper]

Don't look too much into the failed message from testyourvoip.com... I get this on occasion (port blocked message) and I know it isn't since the phone works fine.

[Brian188]

You can change to port 5080 that is the port I am using. Since you are not provisioned you have to do it yourself.

A cable Company may block 5060 because they know that is the port VoIP data traffic uses by most independent VoIP companies. Well, independent VoIP companies are competition to their VoIP service. Look at it this way if you owned a McDonald's wouldn't you want to throw a big black tarp over the Wendy's next door?

[Heat305]

You can change to port 5080 that is the port I am using. Since you are not provisioned you have to do it yourself.

A cable Company may block 5060 because they know that is the port VoIP data traffic uses by most independent VoIP companies. Well, independent VoIP companies are competition to their VoIP service. Look at it this way if you owned a McDonald's wouldn't you want to throw a big black tarp over the Wendy's next door?

Do I still need to contact VT to have them route my line through 5080 on their side? Or just doing it on my side will help? Brian188 I went to TWC local office and they scheduled a Tech to come out to my house. I hate them seriously. Well I will still let have them come out and tell them to give me another modem so I am happy, let's see what he says.. It is scheduled for Monday in the afternoon. Let you know how it turns out. Still no response for my International Block feature. :( I await your answer on the port.

[Brian188]

I just changed the ports in my adapter, never notified VT. I put 1 line on 5080 the other on 5081. Both work beautifully. You may want to forward 5080 - 5081 if you get a router though.

[Heat305]

Are you referring to the screen shots below? I have Line 1 that is set to port 5060 by default. And PSTN Line that is set to 5061 port by default also. Do I need to change both of them even though I don't have a PSTN Line from the local pots company here? Or only change it if I have the ATA connected to a router? Since the SPA-3102 has a router built in as well do I open the ports in there and see what happens? And do I need to use both protocols or just one, i.e TCP/UDP? The screen shots are from inside the ATA settings. And you stated that VT doesn't need to do anything on their side correct?

[dcj65]

Brian188,

If your in the DMZ do you have to port forward still or can i just change my sip port on the pap2?

[Heat305]

Brian188,

If your in the DMZ do you have to port forward still or can i just change my sip port on the pap2?

If your PAP2 is in the DMZ then there is no need to portforward any ports. The PAP has unrestricted access to the internet now.

[Brian188]

Are you referring to the screen shots below? I have Line 1 that is set to port 5060 by default. And PSTN Line that is set to 5061 port by default also. Do I need to change both of them even though I don't have a PSTN Line from the local pots company here? Or only change it if I have the ATA connected to a router? Since the SPA-3102 has a router built in as well do I open the ports in there and see what happens? And do I need to use both protocols or just one, i.e TCP/UDP? The screen shots are from inside the ATA settings. And you stated that VT doesn't need to do anything on their side correct?

Sorry I should be more clear. I have 2 VoIP lines - 1 on 5080 and the other on 5081. So you would only need to change line 1. You will not need to forward ports, on the SPA-3102. If at some point you add a router as I suggested earlier, you may need to forward the ports on that one. If you do forward ports you would use the UDP protocol.

[Brian188]

Brian188,

If your in the DMZ do you have to port forward still or can i just change my sip port on the pap2?

If your PAP2 is in the DMZ then there is no need to portforward any ports. The PAP has unrestricted access to the internet now.

That is correct no need to forward ports. You can change the SIP port on the PAP2 but if you are provisioned, the change will not stick. You will have to contact VT to make the change for you.

[teh_chris]

Yes I am getting "Broken Audio" or "Choppy Audio", whichever you prefer. I haven't had any dropped calls thank god. when I download large files.

are you using bit torrent? i have found that BT will run amok on your home lan without QOS. to fix the problem, i relegated BT to one machine with a static IP and then told the QOS config to bulk ALL traffic to and from that machine.

for BT, i have a VMWare virtual machine running (windows 2000 pro and uTorrent) on my linux box and saving data to a network share. you can set utorrent or azureus to import torrents saved to a given directory, so you don't have to surf for torrents on the bit torrent machine.

i also gave my ATA a static IP and set it to have priority above all other traffic.

the results are nice. i can leave BT running 24x7 and no one complains that the internet is slow and WoW, LoTRO and the like don't produce jitter on the phone.

the QoS package i use is built into openWRT (http://openwrt.org) and x-WRT (http://x-wrt.org) which i flashed my linksys wrt54g with.

in case you are not a linksys router freak... openWRT is like upgrading your PC from linux to openBSD and x-wrt is like installing kde on your linux box.

it sounds like a lot of work, but it's really not if you do your homework before getting started. if you run servers and stuff from your house x-wrt makes port forwarding a real snap (most linksys firmware limits you to 10 or 20 ports... openWRT is unlimited).

I don't experience the same with my TWC line when downloading the same files.

i am not an expert by any means, but i think the digital phone services from cable companies do not use the public internet for calling. yes it's voip, but it's more like the connection between two computers on a switch at your house than two computers hitting eachother thru the internet itself.

like the intranet at a big company... digital phone connections are way lower in latency because there are fewer hops over much faster connections. i think that's why it's *way* more expensive than internet based VOIP (some digital phone services can cost as much as $40 a month).

[Heat305]

are you using bit torrent? i have found that BT will run amok on your home lan without QOS. to fix the problem, i relegated BT to one machine with a static IP and then told the QOS config to bulk ALL traffic to and from that machine.

for BT, i have a VMWare virtual machine running (windows 2000 pro and uTorrent) on my linux box and saving data to a network share. you can set utorrent or azureus to import torrents saved to a given directory, so you don't have to surf for torrents on the bit torrent machine.

i also gave my ATA a static IP and set it to have priority above all other traffic.

the results are nice. i can leave BT running 24x7 and no one complains that the internet is slow and WoW, LoTRO and the like don't produce jitter on the phone.

the QoS package i use is built into openWRT (http://openwrt.org) and x-WRT (http://x-wrt.org) which i flashed my linksys wrt54g with.

in case you are not a linksys router freak... openWRT is like upgrading your PC from linux to openBSD and x-wrt is like installing kde on your linux box.

it sounds like a lot of work, but it's really not if you do your homework before getting started. if you run servers and stuff from your house x-wrt makes port forwarding a real snap (most linksys firmware limits you to 10 or 20 ports... openWRT is unlimited).



i am not an expert by any means, but i think the digital phone services from cable companies do not use the public internet for calling. yes it's voip, but it's more like the connection between two computers on a switch at your house than two computers hitting eachother thru the internet itself.

like the intranet at a big company... digital phone connections are way lower in latency because there are fewer hops over much faster connections. i think that's why it's *way* more expensive than internet based VOIP (some digital phone services can cost as much as $40 a month).

Yah I pay more for my Digital Phone line that's why I am getting rid of it and they don't even offer a control panel so I can enable and disable features like VT offers me. I have my Linksys SPA-3102 connected directly to my cable modem no routers. I do use BT but have not used it since testing VT service I made sure of that. I am the only one that knows what its for and to be on the safe side I uninstalled so when I am not at home my wife or kids don't click on any links on the web launching Azureus. VT tech support recommended me changing my RTP settings. I am testing that out right now to see if it helps. Will let you know how it turns out. I don't have any servers at home either. Thanks for the info