Subject: Re: where is ifp->if_baudrate used?
To: David Young <firstname.lastname@example.org>
From: Jason Thorpe <email@example.com>
Date: 03/19/2007 11:13:27
On Mar 18, 2007, at 3:41 AM, David Young wrote:
> I question whether any single rate suffices to describe many links.
> Consider that commonplace link technologies use multirate PHYs (56k
> modems, WLAN, powerline). Also, a single ethernet/WLAN/powerline link
> may connect multiple stations. The NIC may use a different rate to
> transmit to each station. How can a single rate characterize such a
The intent would be to update the value with the current rate being
used by the link.
> Now, suppose we treat ifi_baudrate as a maximum PHY bit rate. I feel
> dissatisfied comparing a 108 Mb/s WiFi link with a 100 Mb/s ethernet
> by their ifi_baudrate, if the former ifi_baudrate is set to 108 *
> and the latter to 100 * 10^6. To make an "apples with apples"
> of the two links, I need more information than the ifi_baudrate.
> A slightly more practical measure of link speed tells how many
> ifi_mtu-sized link-layer payloads you can send using the top PHY
> figuring in all of the overheads; call this the "speed limit" on the
> David Young OJC Technologies
> firstname.lastname@example.org Urbana, IL * (217) 278-3933