Hi
We are planning to implement VoIP solution using sip server. What are the things we need to look out for or can anybody recomend any VoIP service provider who thay have used.

Regards

We backhaul all of our voip traffic into our call manager. Make sure you are running a decent version (8.0+) that supports GroupQOS. And make sure you know what you are doing, with said qos.. LOL. Other than that.. its a snap.. prioritize the traffic, and it'll make its way to the provider somehow. I was thinking about putting up a dish and running a sip phone back to an asterisk server.. but haven't had the time to do it.

Do use very long passwords on your router(s) and change them regularly and immediately if anyone who knows them leaves your organisation.

VoIP and fraud go together. Try <voip fraud> into Google  2,090,000 pages.....

Best regards, Eric.

Be sure that CRTP compression is turned off, it caused huge random havoc on our VoIP phones last winter.

Apparently this has been fixed in later versions.

PV

We try not to use any CRTP compression.. It really doesnt give much latitude bandwidth wise. And as far as passwords go.. we have TACACS+ deployed network wide.. I'd recommend that for anyone with more than a handful of gear on their network.

What about SAR?  Should that be enabled or disabled?  How big should the segment size be?

What other things could be done to the configuration to enable the VOIP over an iDirect SCPC link to work better?

TIA (FYI we are using 7.1.1 version)

Pat Gannon wrote an interesting article about this including reference to Segment Assembly & Reassembly (SAR) here https://isp-lists.isp-planet.com/isp-satellites/0412/msg00023.html

In my experience it helps if the phone itself puts several speech samples (e.g. 3) into one packet.  

Best regards, Eric.

I would NOT attempt voip on pre-8.0 versions. There is no reason to give yourself the heartache. Use groupqos on 8.0+ and give yourself some time to have a life. Seriously, there's no reason otherwise.

7.x and a VoIP (both over SIP and IAX2), running really well. Why would there be any problems with 7.x?

I am with Max on this one....havent had any issues with VoIP - pre-iDS 8.x.  Things ran well back then.  I will say that I think GQoS needs to be flattened out a bit.  Maybe remove a few layers.....simplify it, so to say...

How do you guys have the QoS set up?  TIA

Hi,
I am configuring the QoS for our iDirect VSAT network, must we turned off the CRTP compression   in iDirect 6.X?  To fix a voice quality problems in our network?

Best regards

6.X?  The precursor to what you are doing (VoIP) should be an iDS/IDX upgrade.  

iDS 6.x is 5-6 yeears old (depending on the actual version you are using) and you really need to consider an upgrade.  There is a laundry list of bugs associated with 6.X, if you need a justification.  That, and the fact that iDirect is about to kill support for it (they are close, I know this).

CRTP.  I would recommend testing it (on and off)...in a lab if you can....while sniffing/wiresharking... to see IF the setting is value added to your configuration.   I havent seen much value in it, but the way I do business is much different from other ISPs.

As it was mentioned above by wbailey you need to be prepared to mark that VoIP traffic to get the neccessary priority when the PPs are allocating BW to your node (for VOIP).  If you dont take care of that RTP, it could wait behind someone watching YouTube or surfing the web.  Make sure you take care of it.  I know you are using a legacy iDS but 6.X does allow you to identify the traffic (in generic traffic profiles) and allocated BW to it. There isnt as much fidelity as the later iDS's/iDX's but 6.x CAN do it...it is just very primitive.