Vpn with bandwidth optimization

Dear ALL,
I need a help for build a server with bandwidth optimization of voip traffic.
I am tell in details, some people doing a vpn with voip device by a linux PC. the pc is connected with 256KBPS (Duplex)internet connection and other side it is connected with voip device by local IP. then the give us a IP with a prefix, we send traffic to the ip with the prefix and all calls is connected with the device.
We know that they have a asterisk server with VPN tunnel and it is connected with the linux pc. when we send traffic it is hit the asterisk server and then it goes to the pc by VPN and the pc is connected with the device and all calls is pass the device.
If anyone know this process how can it be developed please let me know, it will very helpfull for me.
If i doing normal vpn it connect 17 calls by the 256kbps internet but by the procedure it connects 32 calls at a time. As I know the optimize bandwidth with there asterisk server and send traffic the device. so please help me to build this type server.

There is no way that 256kbps, or 256Kbbps will supoort 32 speech calls if the media actually flows through a part with that limit. It would amount to 8kbps, The overhead for RTP is more than that, and that bit rate would only be achieved with a very aggressive, speech only, codec.

Even 17 would be under 15kbps, which is probably still less than the overhead, even if you use extended paacket lengths. (The payload rate for G.711 is 64kbps and the rate with overhead is over 80kbps.)

The only way you will get large numbers of voice calls over such a network is by setting directmedia to yes, and avoiding anything that would require speech to pass through Asterisk (monitoring (transcoding, voice announcements, music on hold, the ability to request features with DTMF), conferencing, etc… This will only help for calls for which both parties are on the same physical LAN, so are not subject to the 256kbps limit.

You may be able to support a limited number of channels using features like teh above at any one time. That still means you cannot use DTMF to invoke features, as that would normally have to be enabled for all channels.

Suman is quiet right. You can run more than 32 port with 256Kbps.
There is a option to ommit extra IP Overhead. then u can run G729 calls with even 7Kbps per calls.

with this technique Some ppl are running 76 call on a 512 Kbps speed in Egypt, Bangladesh, Pakistan.

I already develop the billing to do that things with asterisk and sells on several provider.
They are using the technology.

Otherthan the asterisk there is another Auto provisioning system to get configuration automatically from the server as per the machine MAC.

Dear abdsmd
how you develop it pleas help me about it. can you tell me details by a email.
may email id is - rd-telecom@hotmail.com
web - www.rdnetworkbd.com

hello all,

at last i successfully run asterisk for bandwidth optimize solution feeling great :smiley: & happy :laughing: .

Rjn Ahmed
Skype: r.ahmmed

Don’t you think it would be nice to share you solution with the other forum members? Your advice might help out someone who is in a similar situation as you.

hello please i can run call by iax peer but it take 5KB per call which is 33kbps. please can you help me by your solution i need it badly. my email address is adnanbd00@gmail.com skype id is: adnanbd00 i have billing and everything but Per call it take 4.5 that almos 5KB
i will pleasure to you please.

This thread is over 8 years old and the last activity was almost 7 years ago.

Hardly anyone uses IAX2 these days, and the vast majority of people do not have the bandwidth constraints that would justify it on the basis of its ability to multiplex media streams.

I presume 5 KB (5 *1024 * Bytes) should read 5 kb/s (5 * 1000 bits per second). I’m not clear that that actually represents, as I think no codec running at that rate would be acceptable in anything except a disaster situation. I’d suggest that you needed at least 8kb/s for a barely commercially acceptable quality.

I don’t understand where the 33 kb/s comes from and how it relates to the, presumed 5 kb/s figure

actually i want to run 32 g729 call with 256kbps in rural area still bandwidth is low in there some service is still running with iax2 when i pass a call over IAX i check bandwidth use its showing 4.15KB 4.15KB*8 =33.2kbps

Assuming the standard 8000 b/s rate, 32 G.729 calls over 256 kb/s is not possible over IP, as it makes no allowance for physical, link, network and UDP (transport) overheads, even before the VPN overheads.

With standard 20ms trunked packets, the IAX2 overhead, alone, will be 54.4 kb/s IP and UDP overheads will be at least 11.2 kb/s. That still leaves the physical, link and VPNs, which probably come to something similar.

You might reduce the effect of the overheads by using a lower packet rate, but that will increase latency, and, at some point, will exceed MTUs, increasing overheads, and possibly breaking things.

4.15KB/s is 33.9968 kb/s, not the figure you gave. I still can’t see what this represents.