Ray, re: the T1 part of your double feature post
"I just called Qwest about installing a T-1 line to my residence. They told me that the monthly fee would be $250, or $1,050 per month if I were to use it for Internet connectivity."
In addition to the metallic loop, what does the $250/mo cover the cost of? Channel terminating equipment and framing? Does the circuit travel through sagebrush from your home, all the way to the CO, and die on the frame on four wire terminals?
I went to the Q site and I cannot find the offer, only references to DS1 services. In short, a T1 line supports and is in many ways related to, but different than, a fully compliant DS1 service. The line section is T1, but the logical construction of the signal is DS1, or "digital signal at level one."
It's helpful to think of it in this way: While T1 lines support DS1s, DS1s also exist in environments other than T1 lines. Such as in multiplexing stages of CO and CPE equipment, and in microwave radio terminal gear, for example. The DS1 pulse train is also sufficiently complex, comprising a number of logical characteristics, besides, which connotes a dynamic, intelligent quality. This stands in contrast to the rigid characteristics of the T1 line, which are fairly mechanical and dumb, in comparison.
There are several ways that an ILEC can provision a "T1 Line" over which a DS1 service can be supported. It can be a traditional 4-wire copper-metallic circuit with repeaters placed at 6000' intervals, or it can be a 4-w or 2-w HDSL or ITU-SDSL line.
Some ILECs will start providing, if they haven't already, T1 line services via wireless xMDS, too.
In any event, if it's a DS1 service, then it includes framing and channelization, which allows for the provisioning of multiple services (usually up to 24) over the same access loop. The line must also be synchronized, which means that it must be in synch with a central timing supply _or_ timed to a GPS signal, or a Cesium atomic clock source that is within so many parts per 10 billion of a specified clock rate. In other words, a DS1 service is not simply a metallic loop.
Rule of thumb is that a T1 line costs anywhere from 8 to 14 times the cost of a voice grade channel or circuit. There are 24 voice channels, or DS0s, in a T1. Say, 11 times as much as a DS0. What is the cost of a metallic loop? $24/month? Using this r.o.t., that would put the cost of the T1 line at $264/mo. That's close enough. [This rule really didn't apply to metallic line equivalents, per se, but I tried it here and it worked. It applies, instead, to already-channelized DS0 costs, such as a T1-derived 64 kb/s DS0 service that could be leased separately. Once you reach 8 to 14 of these, depending on specifics, you might as well lease the whole T1, because to lease additional DS0s beyond the breakeven point would not make any sense.]
If the T1 line that you have been quoted is merely a metallic loop that is capable of supporting a DS1 signal (which means that it must meet metallic transmission parameter limits for attenuation vs. frequency and noise limits, among other tests), then it's considerably less complicated than a full-blown DS1 service, leaving most of the hardware provisioning (and some of the engineering) to the end user. Consequently, it is also less costly than a full-blown, end-to-end DS1 service.
In any event, you don't go anywhere for that price and configuration. It's just a dumb access pipe, from which you must be mapped to another circuit to complete your path, which could be any number of services. However, anything you wish to connect to costs extra. Your 250/mo is for being positioned in the CO for the ability to connect to other high-bandwidth services at the T1 rate. Or, if you have a channelized service (which means that you have the ability to map up to 24 subrate channels) then you can access multiple other services, and each of 'those' 24 channel mappings comes at and additional cost, as well.
In and of itself, the T1 loop is merely an access pipe that is connected to nothing. When used in a live application, it is usually a sub-component of a larger, end-to-end service, or an access link to a shared service, such as the Internet or an intranet.
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The T1 offering to the Internet at $1050, OTOH, is anywhere from $1,000 to $2,000 less than an equivalent service just a couple of years ago, if they are giving you a full T1 port into the 'Net. But you have to be careful here.
Does the service for $1050/mo assure you that you are getting a T1 router port directly on the Internet? And what exactly does a T1 router port directly on the Internet mean, anyway?
Your T1 may be one of many going to ports on an ATM switch or a concentrator, which, in turn, feeds an edge router running with a fractional T3 rate, or at a full T3 rate, pointing to the core.
The danger here, of course, is over-oversubscription by the carrier, which means that they have gone beyond what are deemed acceptable statistical limits in piling end users onto the access switch (surely a subjective argument, at best), without making accommodations on the upstream bandwidth provisions to offset the extra load.
We always expect that there will be some degree of oversubscription (as opposed to over-oversubscription), but some SPs - especially cash-strapped ones, and those who are just being overly zealous in trying to achieve profit maximization - have been known to blatantly overdo the matter.
[[[This is not an area that can be controlled very effectively, assuring that end users (especially residential ones) are getting a fair shake, unless there are SLAs at work. And SLAs introduce other problems, and they are hardly the sort of thing that residential users want to get involved with. Actually, SLAs have, by and large, proved to be so much b.s., when you get right down to it. But they are essential, nonetheless, as a signal to the carrier that you just might have the gumption at some point (especially during outages, if rebates are stipulated) to look at what they are doing and demand compensation for damages (which is a demand, very often, that the the user must initiate when an SLA infraction occurs, which requires monitoring and a fair level of diligence), if nothing else.]]]
When you have your own DS1 port into the 'net cloud, during peak usage periods you are "more" likely to have access to a greater amount of bandwidth than when you enter a concentrator or a front end feeder switch. Provided, of course, that in the case of the T1 port directly into the 'net that the router is set up in a "fair" manner for all user-side ports. This is not something that you can always bet on. Going forward, the opposite actually will hold true.
If there are different SLAs that you can opt for on this service, for different levels of QoS, say, or if there are restrictions of one sort or another that you must subscribe your way around, then you can rest assured that unless you subscribe to higher levels of service you will at best be treated on a best-effort basis sooner, as opposed later, upstream, when your flows are deeper into the core. While those who are subscribing to a higher SLA are getting a "fairer" share of the pie, sooner.
And then there are the other Internet service elements, such as mail, directory services, etc. that are usually offered with "T1 Internet access." As in the case above - i.e., the T1 line for $250/mo - what are they offering you when they say T1 Internet access for $1050 per month?
Pricing flavors in my area are all over the map for enterprises, but for residential users I seldom come across T1s to the "residence" anymore, ever since DSLs have been made available at fractional T1 and T1 speeds, symmetrical. The ILECs don't offer these yet (unless you want to include HDSL in this category), but I suspect that they will, soon, due to the ITU ratification of symmetrical DSL recently. Those residential/sohos who I know who would be ordering high speed services these days are now going to a Covad, or to one of the other dsl providers who can do symmetrical service at better than a half T1, and support SLAs with Layer 2 tunneling, and so on. The ILECs aren't there yet for this class of user.
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Stay tuned for my reply to your second feature, concerning fuel cells and co-generation, later this weekend. |
