Q:Why router with ATM interface comes out earlier than pure SONET interface?

Mon Aug 3 02:02:33 UTC 1998

Hi friends,

I find in an article, and it says: in 1995,1996 most nationalwide ISP face the demand
of higher bandwidth than T3, and at that time the only avalible high bandwidth interface
in router in ATM port(say 155M), then this makes many of them choose ATM as their 
backbone tech. Later, Giga router with POS(Packet over SONET/SDH) 155M(or higher) 
interface comes out, then the situation is changed.

Then my question is: why 155M ATM interface is easier to make than 155M POS interface?
Although the net capacity of 155M ATM is less than 155m POS, their capacity for IP packet
is really close. I think its nearly the same challenge to pump up a 155M ATM pipe as a 
155M POS pipe with IP packet for a router.

Thanks for any comments.

Yu Ning.
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Yu Ning
ATM R&D Center of
BUPT (Beijing U. of Posts&Telecom)
Beijing (ZIP:100876, MBox:147#), P.R.China
mailto:yuning at mindless.com or yuning at 263.net
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