Omniswitch 6800-48; 10/100/1000 Crossover Supported; Autonegotiation Guidelines - Alcatel OmniSwitch 6800 Series Network Configuration Manual

Ethernet Ports Overview

OmniSwitch 6800-48

The OmniSwitch 6800-48 stackable workgroup switch has 44 unshared auto-sensing and auto-MDIX
copper RJ-45 10/100/1000 Mbps ports (ports 1–44). In addition, the OmniSwitch 6800-48 has four combo
ports (ports 45–48) that are shared between four copper RJ-45 10/100/1000 Mbps ports and four SFP 1000
Mbps (1Gbps) ports. See the OmniSwitch 6800 Series Hardware Users Guide for more information on
OmniSwitch 6800-24 hardware features.
OmniSwitch 6800-48
TM
Speed 1 3 5 7
OK PRI
PWR BPS
FAN TMP
XFP1 XFP2
Speed 2 4 6 8

10/100/1000 Crossover Supported

By default, automatic crossover between MDI/MDIX (Media Dependent Interface/Media Dependent Inter-
face with Crossover) media is supported on OmniSwitch 6800 Series 10/100/1000 ports. Therefore, either
straight-through or crossover cable can be used between two OmniSwitch 6800 Series switches as long as
auto negotiation is configured on both sides of the link. See
Settings" on page 1-15

Autonegotiation Guidelines

Please note a link will not be established on any copper Ethernet port if any one of the following is true:
The local port advertises 100 Mbps full duplex and the remote link partner is forced to 100 Mbps full
•
duplex.
The local port advertises 100 Mbps full duplex and the remote link partner is forced to 100 Mbps half
•
duplex.
The local port advertises 10 Mbps full duplex and the remote link partner is forced to 10 Mbps full
•
duplex.
The local port advertises 10 Mbps full duplex and the remote link partner is forced to 10 half duplex.
•
This is due to the fact that when the local device is set to auto negotiating 10/100 full duplex it senses the
remote device is not auto negotiating. Therefore it resolves to Parallel Detect with Highest Common
Denominator (HCD), which is "10/100 Half" according to IEEE 802.3 Clause 28.2.3.1.
However, since the local device is set to auto negotiating at 10/100 full duplex it cannot form a 10/100
Mbps half duplex link in any of the above mentioned cases. One solution is to configure the local device to
auto negotiation, 10/100 Mbps, with auto or half duplex.
page 1-6
9 11 13 15 17 19 21 23
10 12 14 16 18 20 22 24
10/100/1000 Mbps Copper RJ-45
Ethernet Ports 1 through 44
OmniSwitch 6800-48 Front Panel
for more information.
OmniSwitch 6800 Series Network Configuration Guide
Combo 10/100/1000 Mbps Copper
RJ-45 Ethernet Ports 45 through 48
25 27 29 31 33 35 37 39
26 28 30 32 34 36 38 40
"Configuring Auto Negotiation and Crossover
Configuring Ethernet Ports
41 43 45 47 LINK/ACT
45 47
46
48
46
42 44 46 48 LINK/ACT 48
Console
46 48
Combo 1000 Mbps SFP
Ethernet Ports 45 through 48
November 2004