Date: Thu, 17 May 2001 15:32:40 -0700 From: "pan" <pan@syix.com> To: <freebsd-questions@FreeBSD.ORG> Subject: Re: TX underrun, increasing TX threshold Message-ID: <003801c0df21$4874c1a0$2813933f@cat> References: <SAK.2001.05.17.glaheoko@support10>
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From: "Peter" <fbsdq@yahoo.com> Subject: TX underrun, increasing TX threshold > What exactly does this error mean and how can I avoid it? > [It appears while doing heavy/big file transfers between my LAN on my dc0 [linksys] ] Newer Linksys seem to have (ADMtek AN985) chips instead of the (82c169 PNIC) ones. (check your boot message). The dc0 driver never produces the underrun event with the PNIC while with the ADMtek it does. What it is, bascially, is that your system could not produce data fast enough for your nic. There's more to it - buffer size etc, but the message says that your system has decided to increase the number of bytes to fill the buffer before the nic can send. This can occur more than once after a boot until the system and the nic are happy with each other - once a reset is found the messages stop and everything is ok. if you reboot you will see the messages again. the event occurs only within a LAN where you have a linespeed greater than 10Mbs - if you were only trafficking through your gateway to the net (via a dsl bridge/router for example) at the max linespeed of 10Mbs you wouldn't see the message. I bet you only see it when you reach > n x 1024kbps linespeed within your LAN. I think the dc0 driver intializes the nic with too small a number of bytes - it certainly isn't true on the physical layer that the system hardware can't keep up with the nic - it's a handshaking thing. Corrections and additions welcome. Pan > > > _________________________________________________________ > Do You Yahoo!? No. > Get your free @yahoo.com address at http://mail.yahoo.com No thanks. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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