need UC500 with many analog/FXS ports

Unanswered Question
Feb 11th, 2009

I need to build a UC500 based system with a lot (almost 20) of analog ports for physical FAX machines. It seems like the most I can do on the box itself is 4 FXS ports therefore I am looking at ATA devices. I have several questions concerning this:

1) Which impedance version for use on North American FAX machines

2) I think I want to go H.323 to save on licenses. Will this work for FAXes and how hard is this to do?

3) Lastly, is this the best way? Other ideas?



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Overall Rating: 4.5 (2 ratings)
Nicholas Matthews Wed, 02/11/2009 - 13:27

Hi Diego,

I think your best option is a VG224. You can configure the VG224 FXS ports to register as SCCP to the UC520.

The impedance for the US is 600 real Ohm.

With the VG224 you could use SIP/H323 or SCCP. SIP/H323 will both save ephone configurations, especially since fax machines don't necessarily need any features.

It will not be that difficult, a few dial peers and you will be mostly done.

I think that VG224--H323---UC520--PSTN is your best bet.



DIEGO ALONSO Wed, 02/11/2009 - 14:15

The VG224 looks like it will do the job but it is very expensive! Comparing that to an ATA186 it looks like you pay about $200 per port with the VG but only about $70 per port on the ATA186. I guess one reason for this is that it is easier to manage 1 VG224 that 12 ATA186's but are there any other reasons to justify the high cost per port?



Paolo Bevilacqua Wed, 02/11/2009 - 14:20

In my opinion the reason of the high cost of high-density analog devices is to disincentive their use for IP phones and server based faxing.

If unable to buy new, you can always look at the refurbished market.

Nicholas Matthews Wed, 02/11/2009 - 14:25

Hi Diego,

Some reasons:

1) The ATAs are not going to be supported as long as the VG224

2) Managing one VG224 is much easier than 12 ATAs

3) The VG224 supports SIP/SCCP/H323/MGCP just like any other gateway

4) VG224 also supports things like IPSEC, NAT, and routing protocols

5) It is much easier to configure and troubleshoot, as it doesn't have a custom interface

6) It officially supports modems and T38 which the ATA doesn't

7) Various other features like syslogging, EEM scripts, flash, IOS upgrades, IOS features, etc.

There are quite a bit of other things. The ATAs can be a pain since they are more or less their own device. The VG224 is just a FXS concentrated gateway so you can do all of the same commands on it.

You may also want to check out the price/port for the VG204/VG202, which is a similar device to the VG224. You can also look towards a legacy device like the VG248 which should also be able to register to the UC520.



Paolo Bevilacqua Wed, 02/11/2009 - 14:31

Great explanation by Nick, fact is the VG248 is even more expensive per port than the 224.

Remember cisco's pricing rule N. 1:

Cost per port is directly proportional to port density.

This is true for all types of device.

Nicholas Matthews Wed, 02/11/2009 - 14:37

Interesting theory - I never deal with this part.

Doing a quick froogle, it looks like it doesn't hold up with the VG202/VG204/VG224 series.

I think the ATA is probably going to be the best bang for the buck. It's also old hardware and software, and has its flaws.


Paolo Bevilacqua Wed, 02/11/2009 - 15:07

GPL prices:

VG202 $795 = $397 per port

VG204 $1,295 = $323 per port

VG224 $5,395 = $224 per port

VG248 $15,995 = $333 per port

I'm partially disproved in this case, but the VG20x is a newer device, introduced in presence of stronger competition.

The rule works because the higher the density, the less the competition, and the higher the budget of a typical customer.

DIEGO ALONSO Wed, 02/11/2009 - 15:09

Thanks Nick, your info was very helpful. I'll run both by the bean counters and see what they say.




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