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The Question is:
I have found something similar to this titled 'Meaning of Carrier Check
Failure?'; is this a similar problem?
All services and application processes are running fine.
Operator log is filling with the given error message which is repeating
regularly between 5 seconds and 1 minute.
Are there any system parameters to adjust to compensate or is this a hardware
problem?
The Answer is :
Your TCP/IP Services version is not supported and is not supported
on this OpenVMS release, and in need of an upgrade. Please move
to V5.1 with ECO or later (as available). Please also upgrade your
OpenVMS Alpha version to V7.1-2, V7.2-2, V7.3 or later (as available).
A "late collision" is a packet collision that occurs after the window
for a network collision closes. CSMA/CD (Carrier Sense Multiple Access
with Collision Detection) networks function based on signal propogation
across the network; CSMA/CD networks require that the length of the
shortest network packet be long enough to span the entire cabling plant
when transmitted. The width of the permissible collision window is
defined by the maximum permitted span of the Ethernet or IEEE 802.3
network configuration and the length of the shortest permissible packet,
and the late collision error indicates there is too much of a signalling
delay in the configuration, or that there is a network station that is
not correctly detecting signals and thus is not backing off for a retry.
That these collisions are occuring (late) implies that the physical
network cabling is too long, that there are too many repeaters, that
there exists failed network hardware, or some combination of these
factors.
The typical approach toward resolving these errors involves TDR-based
(time domain reflectometer; a device which measures signal reflection)
determination of the cable run lengths and any cable faults that might
lurk, determining the physical lengths of individual cabling runs,
looking for correct terminations and correct cabling, counting the
numbers of repeaters, and similar tasks. You are specifically looking
for any and all violations of the Ethernet or IEEE 802.3 network
requirements.
As should now be quite obvious, there are no OpenVMS system parameters to
adjust nor to compensate for this -- your network has a hardware error.
Related topics include (7105), (3500), (3516), (3632), and (4439).
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