Links on the blink - reprise

Jeffrey P. Oliveto joliveto at
Sun Nov 19 14:17:31 UTC 1995


You state:

     At 05:47 PM 11/17/95 -0500, Sean Doran wrote:
>There are substantial disadvantages, too.
>In order to take advantage of the greater
>port-density(-per-dollar) on FR switches right now, the
>end user has to use FR, which is not always practical
>or desirable.  

One of the reasons why end users find frame-relay undesireable is
that they cannot be assured that their provider is not grossly
oversubscribed on PVC-per-port density. When you buy a T1 private
line, you can be assured that you're not sharing it with 120 other
end-users.  :-)

DS3/DS1 Backbone/Trunk capacity planning principles, whether across a Frame Relay Backbone or Cisco 7000 hdlc trunk network are still the same.  It's just as easy to over configure DS3/DS1 Cisco HDLC trunks as Frame Relay trunks.

Potentially at issue here is not Frame Relay networks as a transport but that a Cisco 7000 can not scale properly to support 120+ end-users. :-)

Modern Frame Relay switches:

1) have sub-msec latency
2) can support multiple trunks at DS3+ (to include ATM)
3) are not burdened with processing any of the IP layer 3 nor routing overhead
4) because of 3 have a cost per port that is 300 to 400% less than a Cisco 7000
5) can have it's backbone shared across multiple services thereby reducing both capitalization and bandwidth expense
6) allow ISP to pass the cost savings on to customers

Jeff Oliveto				|	Phone:	+1.703.760.1764	
Sr.Mgr Opns Technical Services	|	Fax:	   	+1.703.760.3321
Cable & Wireless, Inc			|	Email:	joliveto at
1919 Gallows Road				|	URL:
Vienna, VA  22182				|     NOC:		+1.800.486.9999

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