1
23COM PCI TOKEN LINK VELOCITY XL TOKEN RING CARDS README
3
4Release 0.9.0 - Release
5	Jul 17th 2000 Mike Phillips
6
7	1.2.0 - Final
8	Feb 17th 2002 Mike Phillips
9	Updated for submission to the 2.4.x kernel.
10
11Thanks:
12	Terry Murphy from 3Com for tech docs and support,
13	Adam D. Ligas for testing the driver.
14
15Note:
16	This driver will NOT work with the 3C339 Token Ring cards, you need
17to use the tms380 driver instead.
18
19Options:
20
21The driver accepts three options: ringspeed, pkt_buf_sz and message_level.
22
23These options can be specified differently for each card found.
24
25ringspeed:  Has one of three settings 0 (default), 4 or 16.  0 will
26make the card autosense the ringspeed and join at the appropriate speed,
27this will be the default option for most people.  4 or 16 allow you to
28explicitly force the card to operate at a certain speed.  The card will fail
29if you try to insert it at the wrong speed. (Although some hubs will allow
30this so be *very* careful).  The main purpose for explicitly setting the ring
31speed is for when the card is first on the ring.  In autosense mode, if the card
32cannot detect any active monitors on the ring it will open at the same speed as
33its last opening. This can be hazardous if this speed does not match the speed
34you want the ring to operate at.
35
36pkt_buf_sz:  This is this initial receive buffer allocation size.  This will
37default to 4096 if no value is entered. You may increase performance of the
38driver by setting this to a value larger than the network packet size, although
39the driver now re-sizes buffers based on MTU settings as well.
40
41message_level: Controls level of messages created by the driver. Defaults to 0:
42which only displays start-up and critical messages.  Presently any non-zero
43value will display all soft messages as well.  NB This does not turn
44debugging messages on, that must be done by modified the source code.
45
46Variable MTU size:
47
48The driver can handle a MTU size up to either 4500 or 18000 depending upon
49ring speed.  The driver also changes the size of the receive buffers as part
50of the mtu re-sizing, so if you set mtu = 18000, you will need to be able
51to allocate 16 * (sk_buff with 18000 buffer size) call it 18500 bytes per ring
52position = 296,000 bytes of memory space, plus of course anything
53necessary for the tx sk_buff's.  Remember this is per card, so if you are
54building routers, gateway's etc, you could start to use a lot of memory
55real fast.
56
572/17/02 Mike Phillips
58
59