| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 865.1 | Transmit collision | LEVERS::PAGLIARO | Rich Pagliaro, Hub Products Group | Tue Mar 29 1994 13:39 | 20 |
| Generally, the transmit collision counter is a measure of the number of
times any of the repeater's ports participated in causing a collision
on an attached segment. In contrast, a repeater also detects and
responds to receive-mode collisions where two or more stations
collide on a segment to which a repeater port is connected and the
repeater port is not involved in causing the collision.
Strictly speaking the transmit collisions counter counts the number of
times the repeater state machine enters the TRANSMIT COLLISION state
from any state other than ONE PORT LEFT. (See figure 9-2 of the IEEE
802.3 specification). It should be noted that multiple DECrepeater900TMs
connected to the same DEChub 900 flex channel (IMB) act in concert as a
single repeater state machine. Therefore, the transmit collision
counter of one such DECrepeater 900TM module will increment if a port
of another DECrepeater 900TM on the same flex channel is involved in a
collision.
These counters are maintained by repeater hardware.
-Rich Pagliaro
|
| 865.2 | merci.. | PADNOM::PEYRACHE | Jean-Yves Peyrache Country Support Group France | Wed Mar 30 1994 03:42 | 5 |
|
thanks for this infos
Jean-Yves
|
| 865.3 | Collisions on a TP port ??? | ZUR01::SCHNEIDERR | | Thu Jun 09 1994 09:51 | 4 |
| I saw on our DECrepeater900TM many collisions on the TP ports. How can a
collision occour on a TP port??
Roland
|
| 865.4 | | NACAD2::HERTZBERG | History: Love it or Leave it! | Fri Jun 10 1994 11:08 | 6 |
| Collision happens when the station attached to the TP port transmits
into the repeater at the same time the repeater has traffic from some
other connection (e.g., another TP port, backplane ThinWire or IMB,
etc.).
Marc
|
| 865.5 | There must be | LEVERS::PAGLIARO | Rich Pagliaro, Hub Products Group | Fri Jun 10 1994 11:12 | 14 |
| >> I saw on our DECrepeater900TM many collisions on the TP ports. How can
>> a collision occour on a TP port??
Easily...whenever the repeater is transmitting out a port and a station
connected to that port is transmitting at the same time. While 10BaseT
is a duplex link (i.e. separate transmit and receive data paths), the
devices connected to each end of the link are still half-duplex. A
station detects a collision whenever it simultaneously receives and
transmits data.
Regards,
Rich
|
| 865.6 | Got a better card, then what? | CGOS01::DMARLOWE | Have you been HUBbed lately? | Fri Jun 10 1994 13:53 | 3 |
| What happens when you use full duplex Ethernet cards like the DE 425?
dave
|
| 865.7 | Don't connect a FDX card to a repeater | LEVERS::PAGLIARO | Rich Pagliaro, Hub Products Group | Fri Jun 10 1994 14:09 | 4 |
| Full duplex Ethernet will eliminate collisions but the DECrepeater
900TM (or any 802.3 complient repeater) does not support full duplex
Ethernet.
|
| 865.8 | Full Duplex ethernet cards? | DPDMAI::DAVIES | Mark, SCA Area Network Consultant | Tue Jun 14 1994 17:41 | 12 |
| re: .-1
Digital makes full duplex ethernet cards for PCs (DE 425)? I am
familiar with full duplex ethernet and our bridge implementations, I
just wasn't aware we built cards for systems?
Is this true?
thanks,
Mark
|
| 865.9 | Check UPSAR::ETHERNET | LEVERS::PAGLIARO | Rich Pagliaro, Hub Products Group | Tue Jun 14 1994 18:24 | 10 |
| Digital does not currently build any DEChub-based full-duplex ethernet
modules. I do not know what Digital sells/builds in the way of
full-duplex ethernet adaptors/NICs.
Perhaps you might have better luck asking that question in the
UPSAR::ETHERNET conference.
Regards,
Rich
|