SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Technology Stocks : Ascend Communications (ASND) -- Ignore unavailable to you. Want to Upgrade?


To: djane who wrote (47029)5/16/1998 3:50:00 PM
From: djane  Respond to of 61433
 
NTT protocol boosts SONET/SDH for Internet, LANs

broadband-guide.com

News, May 1998

Asynchronous Transfer Mode (ATM) has another challenger
compatible with Synchronous Optical Network/Synchronous
Digital Hierarchy (SONET/SDH) transmission, thanks to Nippon
Telegraph & Telephone Corp. (NTT-Tokyo). The Japanese
telecommunications giant has announced a new protocol suite,
called "multiple access protocol over SONET/SDH" (MAPOS),
which provides frame-based transfer and multiple access
capabilities over SONET/SDH networks. The protocol could also
be used in local area network (LAN) applications, according to
the company.

NTT claims the new protocol uses bandwidth more efficiently than
ATM and is more scalable than Gigabit Ethernet. The former
claims rest on the protocol's small overhead requirements, the fact
that it does not have to conform to ATM's 53-byte cells with
5-byte headers, and its maximum frame size of 64-bytes. The
scalability claim is based on the current SONET/SDH hierarchy,
which extends beyond the speeds currently envisioned for Gigabit
Ethernet.

The company also says that MAPOS differs from ATM in that it
does not require special patches to accommodate Internet
protocol transmission.

The focal point of a MAPIS-based network is a frame switch
developed by NTT. The switch can be used as a hub of a wide
area or Internet network, or connected directly with an end-user's
workstation. This latter capability opens the door to the use of
SONET/SDH for LAN applications over either fiber or copper,
according to NTT.

NTT is leasing the technology to interested parties. The first
customer is Central Systems Research (CSR). The Tokyo-based
company plans to unveil the coreswitch-80 MAPOS frame switch
and three network interface cards, with an eye toward the Internet
exchange, Internet service provider, and large corporate network
markets. The products should be available next month.

Back to the News Index



Home | Electronic Press Room | This Week in Fiber | Subscribe | 1998 Media Kit | Calendar of Events | Site
Map | Add Your Company | Meet the Publisher | Company Index | Contractors | Categories | Sponsors,
Advertisers | Ask the Expert! | Product Showcase | LiveEvents! | Search

The Communications Web Sites



Broadband Guide | Contractors Directory | LiveEvents! | LIGHTWAVE Xtra! |
Wireless Integration Xtra! | Cable Foreman Xtra! | Cabling Installation & Maintenance
Xtra!

Comments or Questions about this site, please contact the Webmaster.

c Copyright 1995, 1996, 1997, 1998 PennWell Media Online L.L.C.

This page was updated on 6-May-98.




To: djane who wrote (47029)5/16/1998 3:53:00 PM
From: djane  Read Replies (1) | Respond to of 61433
 
AT&T to Employ New Gateway System System

by Stephen Hardy, News, May 1998

broadband-guide.com

AT&T (Morristown, NJ) may be the first carrier to deploy a new
class of crossconnect system designed to ease the evolution to
all-optical networks. With AT&T's stamp of approval on the
concept, the system's manufacturer, Alcatel Network Systems
(Richardson, TX), hopes the system will be on the leading edge of
a new networking trend.

The two companies recently signed a multiyear agreement that
calls for AT&T to test and deploy Alcatel's new Optinex 1680
optical gateway crossconnect (OGX). The system operates in
much the same fashion as traditional crossconnects, but will
accommodate greatly increased traffic capacity. For example, the
scalable system will support a total of 80 Gbits/sec to 2.56
Tbits/sec through anywhere from 32 to 1024 ports.

The system is a response to the increasing need to aggregate traffic
into high-speed channels, such as OC-48 (2.5 Gbits/sec), before
transmission over fiber-optic transport networks, according to
Fred Ellefson, senior director of marketing and business
development at Alcatel.

"In the decade from 2000 to 2010, the transport network is now
going to run at the OC-48, the OC-192 [10-Gbit/sec], and the
OC-768 [40-Gbit/sec] rates. And most of the traffic now is stuck
down at the DS-3 [44.736-Mbit/sec] rate, which is where
transport used to start from. So now you need a way to get from
DS-3 to OC-48, or DS-3 to OC-192, or DS-3 to OC-768.
Because before you go and WDM [wavelength-division multiplex]
stuff and use optical crossconnects, you're going to make sure that
you've got the biggest electrical pipe that you can," he explains.
"And so this optical gateway basically takes you out of the
SONET [Synchronous Optical Network] electrical or asynch
electrical domain and launches you into the optical layer at OC-48
and above."

Currently, add/drop multiplexers perform this kind of traffic
aggregation. "But if you think back to the [early] '90s, we had
M13s that did that [at lower speeds] as well," Ellefson says. "But
what you found was that as your network grew, it didn't make
sense to have 242 M13s at a site; you put in a crossconnect
instead."

Thus, Alcatel is betting that as network capacity increases, carriers
will not want to buy the large number of add/drop multiplexers that
might be necessary to keep pace.

"If you look at the broadband crossconnect market and the
evolution that we're about to go through, most of the broadband
crossconnects that are deployed today are used for restoration,"
says Ellefson. "The AT&T and MCI networks, when you get a
fiber cut, they'll route around them using a broadband
crossconnect. But going forward, in the next decade I think we're
going to see the role of these broadband crossconnects evolve
from being a restoration vehicle to being more of a multiplexing
and, as we call it, a gateway between the sonet layer and the
optical layer."

AT&T is already anticipating this trend as it attempts to cope with
its increasing capacity demands, says Ellefson. Thus, the carrier
asked for a robust crossconnect capable of handling greater
speeds. Alcatel plans to deliver the first units of the crossconnect
late this year. AT&T will conduct lab evaluations through the
beginning of next year, after which deployment into the network is
expected. In addition to supporting SONET traffic, the system
also will accommodate cell-based transmission schemes such as
Asynchronous Transfer Mode and Internet protocol.

AT&T's application of the OGX will include the Alcatel 1320 NM
network manager. The Telecommunications Management
Network-based system will enable the OGX to be integrated with
AT&T's existing network management systems.

Back to the News Index



Home | Electronic Press Room | This Week in Fiber | Subscribe | 1998 Media Kit | Calendar of Events | Site
Map | Add Your Company | Meet the Publisher | Company Index | Contractors | Categories | Sponsors,
Advertisers | Ask the Expert! | Product Showcase | LiveEvents! | Search

The Communications Web Sites



Broadband Guide | Contractors Directory | LiveEvents! | LIGHTWAVE Xtra! |
Wireless Integration Xtra! | Cable Foreman Xtra! | Cabling Installation & Maintenance
Xtra!

Comments or Questions about this site, please contact the Webmaster.

c Copyright 1995, 1996, 1997, 1998 PennWell Media Online L.L.C.

This page was updated on 6-May-98.