>Number:         13565
>Category:       kern
>Synopsis:       Tigon driver is wimpy at packet reception
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 26 15:55:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     Jason R Thorpe
>Release:        NetBSD 1.5W, Jul 26, 2001
>Organization:
Zembu Labs, Inc.
>Environment:
	
Architecture: alpha
Machine: alpha
>Description:
	The Tigon driver uses a small number of receive buffers,
	and has separate receive rings for small (MHLEN), standard
	(MHLEN -> MCLBYTES), and jumbo (> MCLBYTES) Ethernet frames.

	Each ring is 64 entries long.

	When advertising a TCP window of only 128K, the Tigon driver
	drops packets, since its receive ring isn't large enough to
	handle the load.

>How-To-Repeat:
	Blast data at a Tigon/Tigon2 interface, and have the receiver
	advertise a 128K TCP window.

>Fix:
	Probably two-fold:

	- Increase the ring sizes, esp. for the small and standard
	  rings... possibly sliminate the small ring entirely.

	- Implelement 802.3x flow-control.
>Release-Note:
>Audit-Trail:
>Unformatted: