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Service Providers >> Satellite Connection in Africa >> VoIP on shared iDirect

Message started by janewanjiru on Mar 9th, 2007 at 5:09pm

Title: VoIP on shared iDirect
Post by janewanjiru on Mar 9th, 2007 at 5:09pm
Hello all,

I would like to know if anybody has had experience using VoIP on a shared iDirect platform.


Title: Re: VoIP on shared iDirect
Post by Maxim Usatov on Mar 10th, 2007 at 7:47am
It works really well, however there are a few moments:

1) You have to have enough CIR to support each VoIP channel. iDirect has the RTP compression built-in, so each G.723.1 channel needs 11 kbit/s of CIR and each G.729 channel needs 14 kbit/s of CIR. The ISP should guarantee the CIR availability by the SLA on a 24/7 basis.

2) The VoIP traffic should be prioritized on the QoS profile both at the modem and the hub to make sure browsing and other non-realtime traffic won't overlap the voice channel. Some providers can do this - BusinessCom included. Some just put you in a general QoS profile and do not allow any changes.

Once both conditions are met, voice works brilliantly.

Title: Re: VoIP on shared iDirect
Post by gcr on Mar 11th, 2007 at 9:47am
We are using VoIP on 3 iDirect shared locations in Eastern Africa.  Works well. 10:1, and 512/512.  Have VoIP on another location, different service provider, 20:1, 192/768.  At times works well, other times seem to be short of bandwidth on the up side.

Title: Re: VoIP on shared iDirect
Post by alexashinze on Oct 21st, 2007 at 1:44pm
Please give me details of your service provider and their rates let me see. I am in Nigeria and looking for reliable provider on the iDirect platform.

Title: Re: VoIP on shared iDirect
Post by janewanjiru on Oct 24th, 2007 at 8:55am
Dear Alex,

You can have a look at - they cover Nigeria very well using iDirect platform on C-band NSS10 (AMC12), as well as Ku-band IS-10 (PAS10).  They also have contention ratios indicated clearly.  Click on the footprint of the satellite that interests you and the pricing will come up.


Title: Re: VoIP on shared iDirect
Post by pgannon on Nov 5th, 2007 at 10:49pm
As Maxim indicated, VoIP requires CIR (Committed Information Rate) and QoS.  You can oversubscribe the shared service 10:1 or 100:1 and VoIP will still work well if you have enough CIR and if your network operator is competent and experienced in prioritizing VoIP.

The key is to make sure you select a network operator who does not oversubscribe their CIR.  Most iDirect network operators do oversubscribe CIR, and thus they may have periods during the day when VoIP does not work as well as it should because CIR is not available when needed.  

Once you oversubscribe CIR it is no longer "committed."  The post from GCR would tend to indicate a network operator who oversubscribes CIR.  

I never understood why iDirect provided the ability to oversubscribe CIR as an option.  Unused CIR just goes into the shared pool anyway.  As far as I can tell the only advantage of oversubscribing CIR is to allow network operators to mislead customers when they sell them "CIR," just as contention ratios are misleading.  

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