[Asterisk-Users] Port density: DS3 cards?

[John Todd]

At 11:04 AM -0800 12/5/03, Bob Knight wrote:
>Greg Boehnlein wrote:
>>On Thu, 4 Dec 2003, Bob Knight wrote:
>>>Steve Dolloff wrote:
>>>>I would be seriously wary of putting a DS3's worth of voice traffic on a
>>>>TNT.  I don't believe they are rated to handle that much voice.  The
>>>>APX1000 would be a much better platform, but I don't know if you can
>>>>find one used.
>>>>
>>>Skip the TNT's.  They are really a joke.
>>>I will admit, I am a bitter X-Livingston employee.
>>>First Lucent bought us for our cool gear, then they bought
>>>Ascend for sales and marketing......
>>>I still can't believe they kept the TNT alive and killed PM4.
>>
>>The PM3 LIVES ON DUDE! :) I'm all about Livingson, and have refused 
>>to put the Asscend stuff in my data center. Seriously, Jake over at 
>>portmasters.com is doing some good stuff with the PM3. Now that 
>>we've got control of ComOS, it is just a matter of time before new 
>>ComOS releases start coming out for the unit. Several people have 
>>already rolled their own and added a few niggling fixes to the 
>>3.9.1c1 code branch.
>>
>>It would be great if we could find a way to use the PM3 as an 
>>inbound channel bank for Asterisk though. I have like 7 of them 
>>sitting in the back doing nothing..
>>
>I like that idea.
>I wrote all the drivers for the PM3 and it would fairly easy to do.
>Looking at the prices on portmasters.com, you could have a 2 t1 inbound
>channel bank for about $350.  Add another $150 for an extra t1.
>I think we used the same Dallas framers that Digium uses.
>
>I am a very big * fan and I am feeling a little guilty that I am 
>using an ethernet
>only solution.  No Digium cards.  I would really like to support Digium, but
>I do not want to start pluggin any PCI cards into the box other than an extra
>ethernet or 2.  I would love to see Digium come out with a t1/e1 to ethernet
>channel bank.  Compared to when we made the PM3 there are some way cool
>processors with built in TDM and ethernet.
>
>Yo Digium,  I am hanging out here in CA with nothing better to do than play
>with *.  Why don't you contract out and let me and a few of my unemployed
>friends build a little channel bank for you.
>
>--
>Bob Knight
>[-w] the work option
>bk at minusw.com
>925-449-9163


Bob -
    You make two good points:

1) The PM3 might be an interesting and inexpensive TDMoE Device, or 
maybe even a "stupid" IAX2 channelizer.  I suspect that Digium will 
not help you with this unless you allow them to be the "exclusive" 
reseller, since this takes away from their core business of selling 
cards.  However, even with a bit of a markup, this would still be a 
pretty decently priced multi-T1 solution, as long as the used market 
can reliably offer these devices at good pricing.

2) On the larger discussion, a separate device that provides T1 
termination in a more dense footprint than a PC is obviously showing 
some interest, as judged by the number of followup posts on this list 
to my original question.  There are two devices that I see as useful:

   - an FXO and FXS selectable solution, via RJ11 or Centronics-style 
bus connector, in a 1u package that delivers IAX2 out (or, 
sub-optimally, TDMoE)  Options for this would be built-in codecs. 
Pricepoint: <$1100 (the cost of a T100P and a well-equipped channel 
bank.)  To be successful, this device _must_ support FXO and FXS. 
Fail-over dialplans for 911 or other "failsafe" dialing methods would 
be good (typical in such devices.)  There exist already devices that 
fit this description, though they are only SIP or H.323, and they 
tend to be wayyyyy too expensive.

   - a high-density T1 termination system that can handle >8 T1's in a 
very small amount of rackspace.  DS3 de-muxing onboard would be 
optimal, since anyone with >8 T1's is probably getting a DS3 delivery 
method, and removing the M13 mux from the rack would be great. 
Optimally, a 1u rackmount with T3/E3 coax _and_ 28 RJ-45 connections 
(only 17 of which would be used for E3/E1 muxing)  Out of this unit 
would come IAX2 or (sub-optimally) TDMoE packets to Asterisk peer(s).
    This solution quickly gets into the discussion of "why you might 
need SS7 for large installations", but I will not address that here, 
and we'll assume this is all PRI delivery.


JT