Connecting to USRP2 with Thinkpad T61 and UHD

I have a working configuration with my desktop computer but can’t seem
to get it to work with the laptop. When I connect the USRP2 to the
ethernet port (Gigabit) (configured for 192.168.10.1) the link light
fails to go on. I added a second Gigabit interface using a USB to
Gigabit internet dongle at 192.168.10.3. This now shows up as eth1. When
I plug the USRP2 into it the green link light comes on but no activity.
Next I take the network cable connected to my router from the desktop
computer and plug it into eth0. I see a link and activity, eth1 shows a
link but no activity. Next I reverse the two cables, The router cable is
plugged into eth1 the link light is on with activity. The USRP2 is
plugged into eth0 and there is no link at all. Does any one have any
ideas on what is going on? Thank you.

Al W8KHP

On 07/20/2011 10:23 AM, Allen Vinegar wrote:

The USRP2 is plugged into eth0 and there is no link at all. Does any
one have any ideas on what is going on? Thank you.
Al W8KHP
Is it possible that your T61 ethernet port isn’t GigE capable?

Also, there are two problems with the USB dongle setup:

o You assigned it the same subnet address as the other ethernet

interface, so that’s likely to cause routing confusion
o A USB-based GiGe dongle won’t actually sustain 1GiGe rates–the
maximum it could possibly do is 480MBps, but
in reality it’ll likely be closer to 300Mbps, which is only about
1/3rd of what you need.

In the meantime, I had been advised about the subnet address problem and
alternately had one port assigned by DHCP and the other to 192.168.10.1.
The results are the same. Given that the dongle is not a workable
option, I still have the eth0 port not even showing connectivity. The
dongle at least showed connectivity even if it can’t sustain the speed.
The port on the T61 is supposed to be GigE capable, but I can’t get it
it even show connectivity when configured with a fixed address.

Al W8KHP
----- Original Message -----
From: Marcus D. Leech
To: [email protected]
Sent: Wednesday, July 20, 2011 8:22 PM
Subject: Re: [Discuss-gnuradio] Connecting to USRP2 with Thinkpad T61
and UHD

On 07/20/2011 10:23 AM, Allen Vinegar wrote:
I have a working configuration with my desktop computer but can’t
seem to get it to work with the laptop. When I connect the USRP2 to the
ethernet port (Gigabit) (configured for 192.168.10.1) the link light
fails to go on. I added a second Gigabit interface using a USB to
Gigabit internet dongle at 192.168.10.3. This now shows up as eth1. When
I plug the USRP2 into it the green link light comes on but no activity.
Next I take the network cable connected to my router from the desktop
computer and plug it into eth0. I see a link and activity, eth1 shows a
link but no activity. Next I reverse the two cables, The router cable is
plugged into eth1 the link light is on with activity. The USRP2 is
plugged into eth0 and there is no link at all. Does any one have any
ideas on what is going on? Thank you.

Al W8KHP

Is it possible that your T61 ethernet port isn’t GigE capable?

Also, there are two problems with the USB dongle setup:

 o You assigned it the same subnet address as the other ethernet 

interface, so that’s likely to cause routing confusion
o A USB-based GiGe dongle won’t actually sustain 1GiGe rates–the
maximum it could possibly do is 480MBps, but
in reality it’ll likely be closer to 300Mbps, which is only
about 1/3rd of what you need.


Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium

FYI. The GigE port on a T61 is compatible with the USRP2. I’ve used it
two
or so years ago with one.

–Colby

On 07/20/2011 10:09 PM, Allen Vinegar wrote:

In the meantime, I had been advised about the subnet address problem
and alternately had one port assigned by DHCP and the other to
192.168.10.1. The results are the same. Given that the dongle is not a
workable option, I still have the eth0 port not even showing
connectivity. The dongle at least showed connectivity even if it can’t
sustain the speed. The port on the T61 is supposed to be GigE capable,
but I can’t get it it even show connectivity when configured with a
fixed address.

Al W8KHP
It could be that the auto-speed/auto-negotiation on the T61 doesn’t work
quite right.

You might look at “ethtool” to turn off autonegotiation and nail the
speed at 1000Mbits for that port.

I finally solved the problem by getting a Belkin Gigabit Ethernet
expresscard. I can now communicate with the USRP2. Still don’t know why
the ethernet interface on the Lenovo wouldn’t work.

Thanks to all those who responded.

Al W8KHP

----- Original Message -----
From: Colby B.
To: Marcus D. Leech
Cc: Allen Vinegar ; [email protected]
Sent: Thursday, July 21, 2011 1:21 PM
Subject: Re: [Discuss-gnuradio] Connecting to USRP2 with Thinkpad T61
and UHD

FYI. The GigE port on a T61 is compatible with the USRP2. I’ve used it
two or so years ago with one.

–Colby

On Wed, Jul 20, 2011 at 7:26 PM, Marcus D. Leech [email protected]
wrote:

On 07/20/2011 10:09 PM, Allen Vinegar wrote:
  In the meantime, I had been advised about the subnet address 

problem and alternately had one port assigned by DHCP and the other to
192.168.10.1. The results are the same. Given that the dongle is not a
workable option, I still have the eth0 port not even showing
connectivity. The dongle at least showed connectivity even if it can’t
sustain the speed. The port on the T61 is supposed to be GigE capable,
but I can’t get it it even show connectivity when configured with a
fixed address.

  Al W8KHP
It could be that the auto-speed/auto-negotiation on the T61 doesn't 

work quite right.

You might look at "ethtool" to turn off autonegotiation and nail the 

speed at 1000Mbits for that port.


Principal Investigator
Shirleys Bay Radio Astronomy Consortium

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