iSCPC network configuration

Hi,

Understand that iDirect can set a iSCPC link and I want to install a remote-to-remote iSCPC link.

Questions:

1) Can this iSCPC link between 2 remotes iDirect modem directly w/o going thr' iSCPC Line Card?

2) Do i still need a iSCPC Line Card?

Best Regards,

You can run iSCPC between two 5000 series satellite routers (but not the 3100s). You don't need an iSCPC card or a hub for that matter. You do need to make sure you download and install the iSCPC software on the remotes. There is also an installation guide available form the iDirect TAC.

The 5100 is a great iSCPC modem/router since it has all the "stuff" built in that you need to run a good IP circuit - routing, TCP/HTTP Acceleration, QoS, etc.  However it's important to understand that it has limited throughput capabilities.  It is not a replacement for Comtech, Paradise or similar SCPC modems for larger circuits.

The 5100 is advertised as supporting something like 20 x 6.5 Mbps, but this kind of throughput is only possible with maximum sized packets (1500 bytes).  Very few sites, if any, transmit everything in 1500 byte packets.

With current software, the forwarding rates are about 2300 PPS (packets per second).  VoIP, like some other traffic, uses minimum sized (64 byte) packets.  2300 PPS x 64 bytes x 8 bits = 1.177 Mbps total throughput - so you could support a 588 x 588 Kbps circuit if all the packets are minimum sized packets.

Since most traffic is a combination of large and small packets, a reasonable application for the 5100 is perhaps 2 - 5 Mbps divided between download and upload.  The more VoIP channels there are, the less the amount of bandwidth available for data.  18 - 23 VoIP lines (G.729 codec) is the most you can do, with nothing left over for data, so don't use a 5100 iSCPC solution to terminate E1's worth of VoIP.  It won't work unless you're using some kind of packet aggregation appliances to combine lots of small packets into fewer large packets. 

For smaller SCPC circuits, you can't beat the 5100 solution, but you have to really make sure you understand the traffic to make sure the 5100 supports it - otherwise you end up with lots of dropped packets and  you pay for bandwidth you can't use.

By the way, the limitation is a result of the VLAN feature built into the iDirect solution.  If the VLAN feature was removed, the throughput could be significantly increased.  Hopefully iDirect will give us a high performance version some day.

Pat

Business Satellite Solutions, LLC
www.bsatellite.com

Cant argue with that...unless they wanted to terminate that iSCPC link to a Line Card on their hub.

I don't know of any SCPC modem cheaper than i5100 that has an IP router and QoS built in, has no IP interoperability issues and supports 8PSK and TPC.

You have to look at the space segement also.

The modem is cheaper than most yes and comes with a in built router but does not come with all the MODCOD options other SCPC modems have.

Some other modems may be able to save you money monthly on space segment costs that may outweight the costs of a more expensive modem, router and switch for example.

Best to look at all options available.

ScotlandTDMA

Quote:


Hi TG,
you will have to go to your retailer for the SW, iDirect support access is not free, and iDirect do not enter in to support agreements with individuals or end user companies.  iDirect will support the reseller, or service provider.  I don't know where you purchased the modems from, but if it was a reseller of iDirect, they should be able to give you the required SW, both the operate on the modems and assist you in configuring the modems also.
I would recommend approaching the person who sold the units to you. 
when you bought the units, did you specify the use?  what SW has already been loaded on the units?  what SW were you given when you purchased the units?
idirect modems are not simple plug and play devices, they have pretty complex configurations and it needs to be understood exactly how to build them, but then you get what is in my opinion a second to none system.
You can always contact iDirect TAC, they will ask you to verify where the units are from and I hope assist you in understanding who to approach to assist in the configuration.  you can email them, or call.  the details are on their website.  never hurts to call and ask, at least tell them you bought the units and would like to understand how to get help configuring them.  they may point you in the right direction.