Best setup for an ATA - in front or behind a router?

fatherdougalmag

I've noticed a couple of calls can sometimes get choppy audio. It comes and goes and, for the most part, it's negligible. I currently have my Sipura plugged into a port on my Belkin wireless router. That's been giving me jip so I'll probably plump it for a Linksys WRTG54 at the end of the month.

Having said that, I'm wondering if there is something interfering with the throughput on the LAN side. There is no downloading going on. This choppy audio can happen during network idle time. So I'm wondering if I should try plugging my NTL modem into the Sipura and then connect my router to the Sipura. Do I stand to benefit anything by doing this? Or is there something I can configure on the Sipura?

Finally, if I do try switching devices around, I take it I should connect the modem into the WAN port and then connect the LAN port on the Sipura to the WAN port on my router. But then am I going to have trouble with NAT and local servers and things?

JoyPad

If you get choppy audio without any local traffic, prioritisation will not bring you any benefits. Sounds to me like this is due to contention, which is beyond your control.

It's rather difficult to obtain it, but what you need to avoid traffic issues is a minimum guaranteed rate for your internet connection. These are rather expensive (normally required only by bussinesses).

If your router supports QoS, then you can configure prioritisation without having to change your physical connections. Otherwise, you can use the Sipura as a QoS-enabled router, and fight off the other issues that will arise from the configuration change. However, both these solutions will be meaningless if your connection speed is bottlenecked by contention at your ISP.


Cheers,
JP

paulm17781

My setup is

NTL > Sipura 2100 > D-link switch > xbox/pc

This works well other than when NTL drops. :mad:

fatherdougalmag

Thanks for the replies.

JP, outside of the call I am able to download at over 200kB/s so that suggests that there's plenty of bandwidth there. I can't remember exactly, but I think I also tried the softphone and that didn't have any problems. Something else I didn't mention was that I'm using a DECT phone. Maybe there's some interference there. I'll try a fixed line phone when I'm experiencing this problem in future.

In any case, I think yesterday was the first full day of testing the VoIP service in the 'real world' and it didn't go too bad. Just one momentary drop out reported by the other half. That's why I want to try putting the Sipura on the other side of the router so it's not subject to any router mis-behaving.

Paulm, did you need to change the PC/LAN port configuration on the Sipura in any way?

paulm17781

No not at all. I have NTL > Wan Port; Lan Port > Switch (PC & X-box).

paulm17781

Forgot to mention I am also using a DECT phone.

fatherdougalmag

Well I made the switch so we'll see what happens. My NTL connection was up and down all day yesterday but I suspect my Belkin router isn't up to it. Haven't had any downtime since I put the ATA 'in front'.

My next problem is port forwarding. I realise now that I'm contending with 2 NAT routers. I guess I'll just disable NAT on the Sipura.

Thanks for the replies though.

causal

If you have your ATA in front of your router then make sure your ATA has LAN side access enabled, and disable WAN side access - have a peek at this thread

causal