Q) Is it possible to change the link speed/duplex

Hello all,


I'm working on windows XP Ethernet D/D.

My question is little bit related with the IEEE spec, but please answer for
that.


Q) Regarding to Ethernet Phy, is it possible to change the link speed/duplex
without the link dis-connecting?

I'm afraid of my Ethernet_Phy¡¯s indicating the link speed/duplex changing
without any link dis-connecting.


Thank you.


// Daum.

Thomas
Mon Jan 30 22:18:46 CST 2006


"Daum" <daum999@yahoo.com> wrote in message
news:OjomFsgJGHA.3000@TK2MSFTNGP14.phx.gbl...
> Hello all,
>
>
> I'm working on windows XP Ethernet D/D.
>
> My question is little bit related with the IEEE spec, but please answer
> for
> that.
>
>
> Q) Regarding to Ethernet Phy, is it possible to change the link
> speed/duplex
> without the link dis-connecting?
>
> I'm afraid of my Ethernet_Phy¡¯s indicating the link speed/duplex changing
> without any link dis-connecting.
>
>
> Thank you.
>
>
> // Daum.
This is generally automatically detected by the adapter hardware and
proprietary parts of the companion miniport driver. The detection depends on
the adapter's connection to the network. For example, your adapter would
have to be connected to a switch that supported full duplex to allow the
adapter to use the full duplex mode.

If there is any way to control the link speed it would be a setting in the
adapter properties. These settings are mostly adapter proprietary; there
probably isn't a NDIS OID to change these settings.

Good luck,

Thomas F. Divine, Windows DDK MVP
http://www.pcausa.com

pavel_a
Tue Jan 31 06:15:29 CST 2006

You could call NdisMIndicateStatus with general status =
NDIS_STATUS_LINK_SPEED_CHANGE.

However the pre-Vista documentation does not specify clearly
what data is sent with this status.

Per some sources, the data buffer should be an ULONG containing the
new link speed in same format as for OID_GEN_LINK_SPEED.
Per some other sources, protocols should ignore the data in the indication
and instead do query for OID_GEN_LINK_SPEED.

So, if your link speed does not change too often, and you are connected
to a "normal" fast wired network, I would advice to indicate media disconnect
and reconnect, or perhaps even reset.

Regards,
--PA

"Daum" wrote:
> Hello all,
>
> I'm working on windows XP Ethernet D/D.
>
> My question is little bit related with the IEEE spec, but please answer for
> that.
>
>
> Q) Regarding to Ethernet Phy, is it possible to change the link speed/duplex
> without the link dis-connecting?
>
> I'm afraid of my Ethernet_Phy¡¯s indicating the link speed/duplex changing
> without any link dis-connecting.
>
>
> Thank you.
>
>
> // Daum.
>
>
>
>

Maxim
Wed Feb 01 05:28:11 CST 2006

IIRC the ways of changing the Ethernet link speed (via Device
Manager/Properties) are usually vendor-specific, and are usually some custom
OIDs or WMI verbs sent from the property page applet to NDIS and then to the
miniport.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim@storagecraft.com
http://www.storagecraft.com

"Daum" <daum999@yahoo.com> wrote in message
news:OjomFsgJGHA.3000@TK2MSFTNGP14.phx.gbl...
> Hello all,
>
>
> I'm working on windows XP Ethernet D/D.
>
> My question is little bit related with the IEEE spec, but please answer for
> that.
>
>
> Q) Regarding to Ethernet Phy, is it possible to change the link speed/duplex
> without the link dis-connecting?
>
> I'm afraid of my Ethernet_Phy¡¯s indicating the link speed/duplex changing
> without any link dis-connecting.
>
>
> Thank you.
>
>
> // Daum.
>
>
>

Stephan
Wed Feb 01 14:20:58 CST 2006


Daum wrote:
> Q) Regarding to Ethernet Phy, is it possible to change the link speed/dup=
lex
> without the link dis-connecting?

No.

> I'm afraid of my Ethernet_Phy=A1=AFs indicating the link speed/duplex cha=
nging
> without any link dis-connecting.

The link *does* go away before the speed changes. Maybe your PHY does
not inform you about this happening, but it usually should.

Link speed is either configured for a fix value or is negotiated
between link partners. The latter only happens before a link is
actually established (auto-negotiation).

If your PHY only informs you about a speed change, simply either call
NdisMIndicateStatus(NDIS_STATUS_LINK_SPEED_CHANGE) as Pavel suggested
or pretend a link down/up sequence by calling
NdisMIndicateStatus(NDIS_STATUS_MEDIA_DISCONNECT) and then
NdisMIndicateStatus(NDIS_STATUS_MEDIA_CONNECT).

Stephan