Network cable unplugged...?

[Kenneth]

Howdy,

I have five systems networked. Let's call 'em A,B,C,D, and E.

A, B, C, and D, are all connected through a wireless hub.

E is connected to that hub with light ethernet cable (and at a rather
long distance, though not approaching the specified limit.)

While system E runs, it periodically (currently about every fifteen
seconds) and very briefly, flashes "Network Cable Unplugged." Other
than that, it seems to work just fine.

What might cause this to happen, and, is there anything that I can do
about it?

Thanks for any assistance,

 

[Bill]

Define "Light" Ethernet cable.

 

[Kenneth]

Define "Light" Ethernet cable.

I apologize for the sloppy terminology. I believe that it is properly
known as "10 base 2." Its connections are BNC.

Might you assist?

Thanks,

 

[Bill]

Coax can be tricky. Does the hub and/or NIC have a 50 ohm termininator
embedded. If not you need to have a t connector and a 50 ohm terminator on
each end.

 

[Kenneth]

Coax can be tricky. Does the hub and/or NIC have a 50 ohm termininator
embedded. If not you need to have a t connector and a 50 ohm terminator on
each end.

Hi Bill,

Yup, the cable terminates properly...

I should add that the "Cable Unplugged" flag appears much more
frequently where there is lots of traffic to the 10-base-2 system. I
also will add that I am having no trouble sending, or receiving data.
It is just that the flag keeps appearing.

Any further thoughts?

Thanks,

 

[Jack Seredyniecki]

I strongly recommend replacing the coax with twisted pair. It'll save you a
lot of headaches.

 

[Kenneth]

I strongly recommend replacing the coax with twisted pair. It'll save you a
lot of headaches.

Howdy,

I welcome your suggestion, but it cannot be done. The issue is
distance. Before I installed the cable I reviewed these issues with
care. 10-base-2 would not have been my first choice, but the distance
necessitated it...

Thanks,

 

[Jack Seredyniecki]

How far is the distance?

Howdy,

I welcome your suggestion, but it cannot be done. The issue is
distance. Before I installed the cable I reviewed these issues with
care. 10-base-2 would not have been my first choice, but the distance
necessitated it...

Thanks,

 

[Bill]

According to IEEE the max length with no repeater is 185m and I think(there
can be a maximum of 3 repeaters joining a segment)

 

[Kenneth]

According to IEEE the max length with no repeater is 185m and I think(there
can be a maximum of 3 repeaters joining a segment)

Hello again,

Sorry, I goofed...

I meant to type about "500 feet"...

But, please, can we look at the software side of this? Might you know
what could cause the "Cable Unplugged" message to appear (in a regular
rhythm) when, in fact, the cable is not "Unplugged?"

Thanks again,

 

[Bryan Hsu]

Try using twisted pair with a repeater? 10 base 2 is just
too much of a head ache. The only time I have seen cable
plugged/unplugged problems was when there were hardware
problems such as cable or NIC card.

-----Original Message-----

 

[Kenneth]

Try using twisted pair with a repeater? 10 base 2 is just
too much of a head ache. The only time I have seen cable
plugged/unplugged problems was when there were hardware
problems such as cable or NIC card.

Howdy,

I cannot replace the cable...

As I wrote earlier, it is my understanding that the run is too long
for twisted pair...

Thanks,

 

[Bill]

The cable shows unplug because the signaling to the repeater has been lost.
I would start with the following, recrimp both ends with new connectors.
Replace the terminators and T connectors. If you are using solid core coax
there could very well be a break in the core wire causing the intermittent
signaling.

Some have suggested to switch to cat5, although the maximum cable length is
only 100m (328ft) you could easily extend the run to 200m by adding a $40
switch or hub (if a power outlet is available some where in the middle).

 

[Kenneth]

Some have suggested to switch to cat5, although the maximum cable length is
only 100m (328ft) you could easily extend the run to 200m by adding a $40
switch or hub (if a power outlet is available some where in the middle).

Hello again,

I thank you for your suggestions...

The cable runs underground between two buildings so switches, hubs,
repeaters etc. are out.

Do you think that it is actually possible that something like signal
loss at a crimp could cause a very stable (for example, every fifteen
seconds with heavy traffic) cycling of the "Unplugged" signal from
Windows? It was that very stable cycling that brought me to the
conclusion that this was a software rather than hardware hitch.

Thanks again,