----- Original Message ----- From: "Chris Adams" <cmadams at HiWAAY.net> To: <ascend-users at max.bungi.com> Sent: Monday, February 12, 2001 3:26 PM Subject: Re: (ASCEND) Real capacity of a TNT > Don't forget that data has to cross the backplane more than once. First > it goes from the ethernet card to the modem card, and then the modem > card sends the modulated data to the DS3 card. Also, both modems and > the ethernet card are full duplex, and everything could be ISDN, so you > could have as much as 4 * 64000 * 672 = 172,032,000 bits per second. As > I understand it, the backplace is basically a shared 155M ATM, so there > isn't really quite enough bandwidth for the thing to run full speed. > Granted, it isn't likely that you'll hit that, but there is also other > stuff going across that backplane (routing messages, control system > stuff, etc.). I think you will find the TNT has 2 buses used for customer traffic. 1) TDM bus with capacity for 960 full duplex 64k channels. This carries traffic from the ingress cards (DS3) to the modem cards. 2) ATM bus. This carries traffic from the modems cards to the ethernet ports. This means 2 * 64000 * 960 = 122,880,000 bits per second over the ATM backplane. ++ Ascend Users Mailing List ++ To unsubscribe: send unsubscribe to ascend-users-request at bungi.com To get FAQ'd: <http://www.nealis.net/ascend/faq>