>
> I am saying we need to squeeze an ISP into as little rack space as
> possible, and we arent going to retool several hundred
> customers DS1s into
> frame relay DS1 just to do this.
Dan,
I was suggesting using DS3 for frame access on the ISP side, either LEC or
other carrier provided, or via your own equipment a la UUNET.
>
> > > And no, the telco can't provide the DS1's over DS3 or
> OC3. Don't ask.
> > In which country are you speaking of? We have hundreds
> upon hundreds of DS1
> > ports landing on CT3 cards from the LEC.
>
> What part of my statement wasnt clear? The "can't" or the "dont ask"?
Neither were unclear. Both were patently false statements.
> > Sure there is. He was asking about OC3. 3:1:0 muxes are
> plentiful. But
> > you are still terminating DS1s in your POP from the LEC.
> This is less
> > desirable as the number of DS1s rises. If CT3 service is available,
>
> See above.
>
> > and you have more that 8T1s, then get CT3. If not, get M13
> muxes and
> > do the cross-connect yourself.
>
> This isnt a telco facilities issue. This is a rack space saving issue.
Agreed. But what is the best way to do this? Do SmartJacks and 66/110
blocks not take up space? Do M13 muxes not take up space? Note that an M40
router can terminate as many copper-teminated RJ-48x connections as 8 M13
muxes ~ in the same footprint. better yet, a 7513 can terminate 188 T1s via
copper RJ48 (with one POS uplink. Thats 8 DS3 Muxes, which is maybe 4/5 the
footprint (in RUs) of a 7513. Then, you need 8 CT3 ports. That would
require another router, say a 7206. Now we are back to terminating them all
on a 7513 (in terms of footprint). The only benefit then is maintenance and
operations on a router that is packed with interfaces, and the ability to
preprovision. The downside: You now have 9 network elements to manage and
maintain instead of 1. If this were a trivial, port-density wouldn't even
be a buzzword. We'd have lots of little routers and switches.
> Telco-provided-DS3 is not an option. No. It isnt. Full Stop.
Since you appear to (falsely) believe that you cannot obtain CT3 service
from a LEC, please refer to this link for further information. It is called
a Tariff, and is required by ALL LECs who wish to drop a wire into someone's
location to do anything related to moving information from A to B, whether
it be a 2.4kbps SDLC link for an ATM machine, to an OC-192 ADM. They do not
tariff what they don't sell.
http://www.bellatlantic.com/tariffs_info/intra/efftar/va/va217/pdf/e_7_5.pdf
p 28
http://www.bellatlantic.com/tariffs_info/intra/efftar/va/va217/pdf/e_7_2.pdf
p 24 Sec 7.2.8-D-3(g)
Let's understand the problem here. There are three ways you can get DS1
service into a POP, all depends on location and the density of DS1s.
1) Terminate them over twisted-pair. Good for low quantity, or
facilities-restricted locations.
2) Terminate twisted-pair into some M13 device. Good for moderate density
DS1 locations that cannot obtain CT3 service because DS3 facilities aren't
available (or, if this is the case somewhere, are not Tariffed by the LEC).
In the Bell Atlantic/NYNEX region, CT3 service is Tariffed and sold in every
LATA.
3) Purchase a small, medium, or big ass DACS (depending on density), and
interconnect with the LEC over SONET. You can get VT1.5 or M13 muxing over
asynchronously mapped DS3 into each STS1. Depends on the tariff and the
cost. Note that as the router vendors begin shipping high speed interfaces
that do full subrate later this year, such as the CH-OC12 to DS0 services
available on the ESR 10000, you can remove the DACS and just order the
circuit. You can even get protection via APS and have redundancy for all of
your DS1 customers!
I agree that rack space is an issue. I disagree that racks full of M13
muxes are the answer. One or 2, OK. 300, not OK. And believe me, there
are many ISP POPs that terminate more than 1000 T1s.
Now, back to the original question, which was how to get DS1s into an OC3
ATM port. This has nothing to do with the PDH, so lets start the discussion
over and talk about cell relay.
There are lots of ways to aggregate customers. The cheapest solution with
the best performance is Frame Relay. The second is ATM, although I have a
bias toward SMDS. ;). The third is PTP service, with SDSL being cheapest
and costs increasing as you ascend the digital hierarchy. In all cases, PTP
is the best solution if you are in a big city, near a serving office.
Outside of a big city, you must pay distance charges that make the switched
services more attractive. If you have existing PTP customers, than PTP it
is. For new service, you can be competetive with switched service from the
beginning, and sell PTP service to those who really want/can afford it.
If you are in the BA/NYNEX region, you can buy and ATM OC3 circuit for about
$3,500 per month, and order T1 circuits to all your customers and terminate
them on the BA ATM switch. Same cost model across the board. Or, you can
order a DS3 frame-relay circuit and do essentially the same. In both cases,
you pay per-PVC charges, all of which are easily passed on to the customer.
For customers that are 10-100+ miles from your POP, this is WAY cheaper than
PTP service.
Same speed.
Less cost.
More revenue.
Why is this so hard to fathom?
./chris
> -Dan
>
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