Subject: commenting nitpicks in if_sl.c
To: None <current-users@NetBSD.ORG>
From: John Vinopal <email@example.com>
Date: 02/17/1995 18:54:23
* SLMTU is a hard limit on output packet size. To insure good
* interactive response, SLMTU wants to be the smallest size that
* amortizes the header cost. (Remember that even with
* type-of-service queuing, we have to wait for any in-progress
* packet to finish. I.e., we wait, on the average, 1/2 * mtu /
* cps, where cps is the line speed in characters per second.
* E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line.
This last line is quite in error. Waiting for 1/2 of a 1024 byte
packet is 512 / cps. On a 9600 line, cps is 1200. So that makes
a 426ms wait for a 1024 MTU at 1200 cps (9600).
* EG: 426ms for 1024 MTU at 1200 cps (9600)
* EG: 123ms for 296 MTU at 1200 cps (9600)
* EG: 170ms for 1024 MTU at 3000 cps (~26400)
* EG: 49ms for 296 MTU at 3000 cps <-------- typical v.fc
* EG: 142ms for 1024 MTU at 3600 cps (~28800)