Frequent Call drops... no idea why....

Posts: 110 · Vonage Forum Senior Joined: Mar 06, 2004 Posts: 110

I've been using Vonage for about two months now... first month on a trial basis and it worked very reliably. I even have very good experience faxing, unlike many people here.

I've got Optimum Online cable modem, with 8MB upload and 1MB download (so lots of speed). I run no peer-to-peer services whatsoever, but occasionally do download TV shows from other ReplayTV users. However, those downloads are generally throttled down to less than 256K by the sender themself, and never seem to effect my speeds on the PC (and they are only downloads, not uploads).

My problem is that in the last couple of weeks (especially since my LNP went through!), my wife says she's dropping a good number of calls right in the middle of talking. I've had it happen once or twice while I'm talking to here from work or on my cell phone.

I have the Moto ATA VT1005 behind my Linksys BEFSR41 router. The ATA is picking up its IP address from the router (which I have verified) and I have all the recommended ports forwarded. I also have UpNP enabled on the router (or, I should say, it appears to be on by default) because my ReplayTVs use it all the time and they are working fine.

Can anyone else think of what might be causing these call drops? My cable modem grabs one IP from the ISP and that IP address almost never changes.

Posts: 110 · Vonage Forum Senior Joined: Mar 06, 2004 Posts: 110

Wow... that's sort of a long ordeal to go through to have it turn out to be the phone.

Unfortunately, this problem I'm having has occured on a plain old desk phone we use as well as our Vtech cordless phones. This is definitely related to the Vonage service, not the phones.

Any thoughts?

Posts: 9 · New Forum Member Joined: Mar 17, 2004 Posts: 9

When this happens, most often than not, its either your router or the ISP is having problems.

My office has DSL service from SBC, 6/768 service. We had some problems and it turned out to be that our Cisco PIX515 firewall was having problems. We re-routed the Voip calls through a router (made from FreeBSD and a old PC) and problems disappeared.

When you browse the web or even download files, dropped packets are seldom noticed but this can adversly affect a Voip call. To check if you ISP is dropping packets, a simple test would be (assuming you're using Windows) to go to your command prompt (click start-->run and enter cmd) and use this command: ping www.yahoo.com -t

You'll start to see a list of replies coming back to you. If the timing is fairly stable (eg. between 10ms difference and not very high return time like less than 100ms), then the ISP is probaly ok. Hit Ctl-C and you'll get a summary too, see if there are any packet loss. Make sure you let the command run for some time before hitting ctl-C to allow sending many packets.

Cable is shared access and another thing you should also check is for viruses on your home PCs. Many of them can send out tons of rubbish bmobarding all network devices and could cause calls to drop. If you're technically inclined, you can also use tools like Snort to check if any of your neighbours on the same cable service is attempting to knock you offline by doing all sorts of funny thing. You can report this to your ISP if it happens.

Good luck. Surprised

Posts: 110 · Vonage Forum Senior Joined: Mar 06, 2004 Posts: 110

Thanks for the responses.

Moto... I can't turn off UPNP because I need it for my video server (DVArchive) and DVRs (Replay TV) to work properly (not sure if you're familiar with those products, but it let's me control and watch what records on any of my TVs from any of my other TVs or from my PC).

BigBear... I'm pretty good about security and virus updates and eliminating spyware -- I've never installed any of the peer-to-peer services.

Thanks for the add'l explanation re: packet loss. I guess this is why people here suggest running ping plotter for a while (with the demo version that keeps a long history). I'll probably install that over the weekend and leave it running for a while to see if I get any packet loss... right??????

Posts: 183 · Vonage Forum Master Joined: May 05, 2004 Posts: 183

Speaking of looking for packet loss, does anyone know an IP that the ATA box talks to that we could ping? Doing so may be helpful.

Posts: 110 · Vonage Forum Senior Joined: Mar 06, 2004 Posts: 110

OK... so I got ping plotter up and running and saving all data. Sure enough, after my wife told me a call was dropped, I used the Vonage log to track down the exact time of call and used my ping plotter data to show that for about three mins. in there I was experiencing 80 - 100% packet loss. Seemed to have fixed itself without any reboots, but that certainly explains the dropped call. Scanned the ping plot history and found that this seems to happen a few times a day.

Since the ATA is behind the router, I'm pretty certain it's my router or cable modem or ISP causing this, not the ATA. While I do have a decent amount of network traffic on my home network, it's all robust IP stuff that wouldn't really hiccup over a 3 min outage.

So I first replaced my cable modem. Why? A) because it's over five years old and B) the Cable co. (Cablevision) would replace it for free.

Next I've replaced my Linksys BEFSR41 with a (CISCO branded) BEFSR81 v3. Why? Because I'm going to need an 8 port router in the near future anyway and the 81 has some limited QOS features that could be useful with Vonage. No reason to go through diagnosing the problem on the 41 when I'm just getting rid of it in a few months.

So far so good. I've enabled UPnP on the router and changed the MTU size to 1500 per another post on this Forum. I've got ping plotter setup now to send me an SMS message on my phone if it loses any packets again (or jump time > 80 ms).

For now, I've decided to NOT enable any of the port forwarding stuff. While this is not recommended and is far from the consensus view, I believe that if UPnP is properly implementd on this new router then it may not be neccessary (I doubt UPnP was properly implementd on the old router -- I know that the DMZ feature was not).

Calls both ways still working well 12 hours later. I'm going to release / renew the DHCP address I get from the cable system on the router tonight and make sure that I reestabish phone connectivity quickly (typically I hold onto my IP address for months at a time).

If I do have problems, I'm going to put the ATA into the DMZ before I do port forwarding again.

Anything else??????

Posts: 183 · Vonage Forum Master Joined: May 05, 2004 Posts: 183

Sounds good, plyons. One question: Why are you reluctant to use port forwarding?

Posts: 110 · Vonage Forum Senior Joined: Mar 06, 2004 Posts: 110

Well... if it's not really needed (if UPnP is working properly) then I'd rather not.

One reason is that my router table only has a limited number of port forwarding assigments. With my Replay's, gaming, etc. many of them are already used and the Vonage ports filled up the entire table last time.

Posts: 61 · Full Forum Member Joined: Jan 29, 2004 Posts: 61

Just my 2 cents on the end of this. I had many a problesm with my Linksys BEFSR41 router. I replaced it and all my problems went away. I had only done that first I could have saved many days of tinkering with the other componets trying to make Vonage work.

Good move on upgrading your router!