T1 Circuit actual throughput 1290Kbps

Robert E. Seastrom rs at bifrost.seastrom.com
Thu Jul 9 14:18:51 UTC 1998

   From: Dorian Kim <dorian at blackrose.org>

   > A T1 is capable of achieving 1536 kbps maximum (24 x 64 kbps).

   While this doesn't seem to apply to Tony's case, I wouldn't make a blanket
   statements like that. If the T1 is provisioned ESF, yes you can get 
   1536 kbps, but there are places where you still can only get SF/D4 framing.

Precisely.  The most likely explanation is that the T1 is actually D4
framed, which gives it a throughput of (24 * 56kbps) == 1344k.  Or the
T1 may be properly provisioned but the CSU/DSUs incorrectly configured
for the old-fashioned framing (I think I saw this working at one
point, can't remember for sure).  The PPP is hardly eating anything at
all in the grand scheme of things.


More information about the NANOG mailing list