George, to reinforce your statement concerning ASND's intentions in the optical domain...
>>Ascend is going to WDM products big time and Stratus will allow it to interface with all the telco gear<<
...see the following article in the August Lightwave Magazine:
broadband-guide.com
Second thought, since these articles tend to scroll, I'll post it in its entirety below for posterity.
Another article by the same author [Stephen Hardy, editor in chief of Lightwave] in the same issue that speaks to Optical Networking and DWDM, that may be of interest to some, can be found at:
broadband-guide.com
Enjoy, and Best Regards,
Frank Coluccio
==============================
News, August 1998
Ascend enters optical networking fray
By Stephen Hardy
Ascend Communications Inc. (Alameda, CA) threw its weight
behind the push to retire the transmission layer from future
network topologies with the introduction of an OC-48
(2.5-Gbit/sec) interface that enables its new GX 550 "Smart"
Core atm Switch to interface directly into the optical layer. The
company is the second data-communications equipment
manufacturer to unveil an optical internetworking strategy, a move
that reinforces the emerging battle line between traditional
telecommunications-equipment providers and upstart
data-communications companies for control of tomorrow's
network marketplace.
Ascend's announcement represents another attack on traditional
network architectures that contain separate switching and
transmission layers. By incorporating such transmission-layer
functions as grooming and automatic protection switching into the
GX 550, Ascend contends that carriers and service providers will
no longer need Synchronous Optical Network/Synchronous
Digital Hierarchy (SONET/sdh) add/drop multiplexers and digital
crossconnect systems. The result is a combined
switching/transmission layer that is protocol-transparent and
provides a simplified, flexible architecture that carriers will find
easier to manage.
Like Cisco Systems Inc. (San Jose, CA), its chief competitor in
the data-communications arena and the first company from that
community to announce an optical internetworking strategy (see
Lightwave, June 1998, page 1), Ascend envisions that this new
hybrid layer will link directly into the optical layer via
wavelength-division multiplexers (wdms) at OC-48 rates. Both
companies have OC-192 (10-Gbit/sec) interfaces forthcoming but
agree that OC-48 will be the optical internetworking "coin of the
realm" for the foreseeable future.
Unlike its data rival, however, Ascend lined up some customers to
stand behind its claims that optical internetworking can be
implemented today. Both Williams Network (Tulsa, OK) and
Frontier Corp. (Rochester, NY) are testing the switch with wdm
systems. Wayne Price, network-development manager at
Williams, says lab tests of the switch have been conducted
already. Interoperability trials with Pirelli's T-31 omds wdm
system have been successfully completed, while similar tests with
ciena's MultiWave Sentry system were due to wrap up in June.
Field trials of the GX 550 were slated to follow in July and end
this month over a link between Washington and Atlanta. Assuming
a successful completion of these trials, Price says Williams will
then deploy the switch in its fiber-optic network.
The flexibility provided by atm over optical networks will give
Williams a multiservice capability that should prove attractive to
the company's client base of service providers, says Price. The
optical internetworking strategy also will significantly simplify
network topology while ensuring reliability, he adds.
Interestingly, most of the wdm equipment currently in the Williams
network comes from Nortel (Brampton, ON, Canada). But
Williams has no plans to conduct interoperability tests with the
Nortel equipment, according to Price, who cited a desire to
promote a multivendor environment as the reason.
For its part, Frontier will test the interoperability of the GX 550
and the 16-wavelength SpectralWave multiplexer from NEC
America (Herndon, VA). Jim Watts, Frontier's director of
transmission engineering, says tests originally were planned for
June but had been postponed, in all likelihood to July. "It's just a
matter of coordinating with NEC and Ascend as to when
everybody can get together and get the interfaces out to do that,"
he says. "Because we certainly have network available to do it."
The network includes two functional SONET rings of more than
3100 mi each in the western United States as well as additional
routes across the country. More rings are under construction as
part of the company's ongoing cross-country expansion. The
SpectralWave system is an integral part of this infrastructure.
Meanwhile, the GX 550 is being deployed as part of an atm
network that Frontier also has underway. With both pieces of
equipment deployment already, most of the pretest certification
work should be completed when the interoperability tests begin.
Thus, Watts anticipates the test process will flow smoothly. "I
would expect that to get the test up, it wouldn't take more than a
few days to begin testing," he says. Although the test period has
yet to be defined, "I think we'll probably find what we need to find
out within two weeks," he predicts.
For the sake of convenience, Watts believes the tests will take
place close to Frontier's Rochester, NY, headquarters. "We're
probably looking at Rochester to Syracuse or Rochester to
Buffalo - probably Rochester to Syracuse, because we've got an
inline amplifier between there," he offers.
A successful test of the OC-48 interface could prove an important
step in Frontier's plans to expand the capabilities of its network.
For example, the atm network initially will be set up at OC-12
(622 Mbits/sec); should the interoperability test go well, the
higher-speed interface could see deployment starting at the end of
this year. Meanwhile, Frontier has further evolution in mind.
"We're going to have a convergence here of IP and atm," Watts
reveals. "We've got IP over atm, and what we're looking at is a
separate IP network, direct over wdm." The company is
investigating IP routers for such an enhancement, he says.
Ascend also has succeeded in spreading the optical
internetworking gospel to Europe. Deutsche Telekom
Systemloesungen GmbH has selected the GX 550 for use in the
Gigabit Testbed operated by Deutsches Forschungsnetz (dfn). The
dfn network is a computer-based communications infrastructure
for research, science, education, and culture in Germany. The
addition of the Ascend hardware will enable the dfn to provide
stm-16 (2.5-Gbit/sec)/OC-48 atm core connections for the
delivery of video, voice, and data traffic to German universities
and research centers.
Meanwhile, more traditional telecommunications transport
equipment suppliers have begun to adapt their product lines to
meet the carriers' changing needs as well. While it remains too
soon to tell whether companies like Cisco and Ascend will carve a
significant niche for themselves in the telecommunications market,
the willingness of companies like Frontier and Williams to adapt
optical internetworking strategies may indicate that new-generation
carriers, at least, are willing to listen to what data-equipment
manufacturers have to say about the future of optical network
architectures. |
