Skipper,
I read your post on the 1 D/A conversion. I think you are mistaken on two counts.
The first is that a channel bank is required to front end a USR Total Control shelf for T1 access, Most large ISP's get their trunks from a central office or a tandem switch via digital facilities. The Digital signal originates from the switch and most likely remains in the digital format all the way to the T1 interface on the Total Control shelf. If the ISP wants fractional T1 service the LEC normally provisions the number of DS0s requested through a 1/0 DACS. (the DACS is also a pure digital environment).
The second is that ISP's with USR Total Control have been forced to use channelized T1 until recently. USR has been shipping PRI interfaces for the Total Control shelf for more than a year.
In conclusion, I have tested the performance of the many access platforms: Ascend, USR, Primary Access, and Shiva/Nortel's Rapport.
I can tell you that the USR Total Control out performs them all. Ascend has a good ISDN access box, but they are in big time trouble when it comes to their modem technology, Their box can not handle a load at 100% capacity, If 48 analog (non ISDN calls) are originated into the box it locks up. Problems include slow training time, calls not answered, all the way to complete system freeze. Some ISP's solution to the problem was to reluctantly deploy more Ascend boxes and load them at less than 100%. Also Ascend had major bugs in their early products and to think that they are going to take a new Rockwell Chip and integrate in their existing platform and ship by end of 1Q 97 ???
In my opinion if the rumors of a DS3 interface to the Total Control are true, and if X2 is adopted as the 56k standard, Ascend is in big trouble. Also Cascades' new AX box looks like it could also be a contender in the near future.
Good Investing......Wayne Price |
