Subject: [manet] transmission failure info from 802.11 cards

From: Vinayak Naik <[email-masked]>
Date: Sun, 28 Mar 2004 14:16:05 -0500 (EST)

I have a quick question about an ad-hoc network that we are trying
to build with 802.11 cards.

In simulators (such as ns-2), a transmission failure at the MAC layer
results in a callback to the routing layer to try for an alternate route.
However, with real 802.11 cards in a testbed, is it possible to get
a feedback about failure of MAC layer delivery?

Are there any special 802.11 cards that might have this feature?

Thanks,

Vinayak

_______________________________________________
manet mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/manet

---

From: David Young <[email-masked]>
Date: Mon, 29 Mar 2004 11:42:46 -0600

> Are there any special 802.11 cards that might have this feature?

Virtually every 802.11 card provides feedback.  Lucent & Prism cards
will indicate a transmit failure after the retry count has expired.
The 802.11 ASICs by Atheros, ADMtek, and Realtek will tell you how many
times they re-tried a transmission. The hardware capability is there,
however, the Tx-failure indications do not climb the networking stack
to routing daemons.

Dave

-- 
David Young             OJC Technologies
[email-masked]      Urbana, IL * (217) 278-3933