How obtain the best results of a VoIP network with Asterisk?

I am using an Asterisk server installed in an Ubuntu server in an Amazon cloud. Sometimes I am having problems with the quality of calls, is cuttings, I think that this problem happen because the network of the client or the server is busy. How I can check it?

I want to know about routers of specific networks that uses voip, do you recomend to use it? What models recomend to me use in a wireless and cable(4 ports, can use switch to more) network until 12 devices.

Thank you.

Don’t use a cloud server if quality is essential.

really? why? if I use a dedicated server?

Because you could guarantee that all of its processing capacity was available, immediately, for the VoIP, and because you would have control over its network connectively and the loading of that network at least as far devices on your own network were concerned. You could prioritise VoIP for the whole route of internal calls.

If I hire a dedicated server maybe I can resolve it.

But I think that the problem is in the side of the client, for example, my house actually have a small non comercial router, can I priorize the traffic in it?

Domestic market routers are unlikely to be able to prioritise traffic.

Even an up market router can only prioritise traffic on one hop, going away from it.

For most domestic ISPs, the main bottlenecks are in traffic flowing from the internet to the router, and the router can do nothing about those. Although it can prioritise that traffic within your LAN, unless you do everything with Wifi (a non-starter for VoIP), there should be plenty of spare capacity. It can also prioritise traffic on the first hop towards the ISP, but most domestic users only generate small volumes of web page requests, and relatively low volume back channels on incoming streams.

I understand you, but I noted that the problems happens when I was using the videos in the network, like youtube or netflix, and in Brazil the internet band is not so fast, for example I use 15mbps in my house sharing in many devices.

Can you recommend any basic router to allow prioritize the traffics, with a good cost and benefits.

Thank you.