20.1.2 10BASE-T/100BASE-TX/1000BASE-T/2.5GBASE-T

This section describes the interfaces using the twisted pair cable (UTP) of 10BASE-T/100BASE-TX/1000BASE-T/2.5GBASE-T.

<Structure of this section>

(1) Connection interface

10BASE-T,100BASE-TX,1000BASE-T, and 2.5GBASE-T support auto-negotiation. Auto-negotiation is a function for determining the optimum connection operation between devices in terms of transmission speed, full-duplex/half-duplex, and flow control. If auto-negotiation does not resolve the problem, the Switch repeats the connection operation until a link connection is established.

1000BASE-T and 2.5GBASE-T only support full-duplex connectivity with auto-negotiation.

10BASE-T and 100BASE-TX support full-duplex/half-duplex fixed connections in addition to auto-negotiation.

You can configure either of the modes shown below. Select the appropriate mode for the network to be connected. The default for the Switch is auto-negotiation mode.

Auto-negotiation
100BASE-TX full duplex (fixed)
100BASE-TX half duplex (fixed)
10BASE-T full duplex (fixed)
10BASE-T half duplex (fixed)

(2) Connection Specifications

The following describes the connection specifications for transmission speed and duplex mode (full or half) for a connection between the Switch and a remote device.

Because 10BASE-T and 100BASE-TX may not be connected by auto-negotiation depending on the remote device, make the fixed settings that match the interfaces of the remote device as much as possible.

The following tables show 10BASE-T/100BASE-TX/1000BASE-T port-connection specifi cations.

Table 20-3: Connectivity specifi cations (10BASE-T/100BASE-TX/1000BASE-T)
Remote device		Settings on the Switch
Method	interface	Fixed settings				Auto- negotiation
Method	interface	10BASE-T half duplex	10BASE-T full duplex	100BASE-TX half duplex	100BASE-TX full duplex	Auto- negotiation
Fixed settings	10BASE-T half duplex	10BASE-T half duplex	NG	NG	NG	10BASE-T half duplex
	10BASE-T full duplex	NG	10BASE-T full duplex	NG	NG	NG
	100BASE-TX half duplex	NG	NG	100BASE-TX half duplex	NG	100BASE-TX half duplex
	100BASE-TX full duplex	NG	NG	NG	100BASE-TX full duplex	NG
	1000BASE-T half duplex	NG	NG	NG	NG	NG
	1000BASE-T full duplex	NG	NG	NG	NG	NG
Auto- negotiation	10BASE-T half duplex	10BASE-T half duplex	NG	NG	NG	10BASE-T half duplex
	10BASE-T full duplex	NG	NG	NG	NG	10BASE-T full duplex
	10BASE-T full duplex and half duplex	10BASE-T half duplex	NG	NG	NG	10BASE-T full duplex
	100BASE-TX half duplex	NG	NG	100BASE-TX half duplex	NG	100BASE-TX half duplex
	100BASE-TX full duplex	NG	NG	NG	NG	100BASE-TX full duplex
	100BASE-TX full duplex and half duplex	NG	NG	100BASE-TX half duplex	NG	100BASE-TX full duplex
	10BASE-T/100BASE-TX full duplex and half duplex	10BASE-T half duplex	NG	100BASE-TX half duplex	NG	100BASE-TX full duplex
	1000BASE-T half duplex	NG	NG	NG	NG	NG
	1000BASE-T full duplex	NG	NG	NG	NG	1000BASE-T full duplex
	1000BASE-T full duplex and half duplex	NG	NG	NG	NG	1000BASE-T full duplex
	10BASE-T/100BASE-TX/1000BASE-T full duplex and half duplex	10BASE-T half duplex	NG	100BASE-TX half duplex	NG	1000BASE-T full duplex

Legend: NG: A connection is not possible

The following tables show 100BASE-TX/1000BASE-T/2.5GBASE-T port-connection specifi cations.

Table 20-4: Connectivity specifi cations (100BASE-TX/1000BASE-T/2.5GBASE-T)
Remote device		Settings on the Switch
Method	interface	Fixed settings		Auto- negotiation
Method	interface	100BASE-TX half duplex	100BASE-TX full duplex	Auto- negotiation
Fixed settings	100BASE-TX half duplex	100BASE-TX half duplex	NG	100BASE-TX half duplex
	100BASE-TX full duplex	NG	100BASE-TX full duplex	NG
	1000BASE-T half duplex	NG	NG	NG
	1000BASE-T full duplex	NG	NG	NG
	2.5GBASE-T half duplex	NG	NG	NG
	2.5GBASE-T full duplex	NG	NG	NG
Auto- negotiation	100BASE-TX half duplex	100BASE-TX half duplex	NG	100BASE-TX half duplex
	100BASE-TX full duplex	NG	NG	100BASE-TX full duplex
	100BASE-TX full duplex and half duplex	100BASE-TX half duplex	NG	100BASE-TX full duplex
	1000BASE-T half duplex	NG	NG	NG
	1000BASE-T full duplex	NG	NG	1000BASE-T full duplex
	1000BASE-T full duplex and half duplex	NG	NG	1000BASE-T full duplex
	10BASE-T/100BASE-TX/1000BASE-T Full and Half Duplex	100BASE-TX half duplex	NG	1000BASE-T full duplex
	100BASE-TX/1000BASE-T full duplex and half duplex	100BASE-TX half duplex	NG	1000BASE-T full duplex
	2.5GBASE-T half duplex	NG	NG	NG
	2.5GBASE-T full duplex	NG	NG	2.5GBASE-T full duplex
	2.5GBASE-T full duplex and half duplex	NG	NG	2.5GBASE-T full duplex
	1000BASE-T/2.5GBASE-T full duplex and half duplex	NG	NG	2.5GBASE-T full duplex
	100BASE-TX/1000BASE-T/2.5GBASE-T full duplex and half duplex	100BASE-TX half duplex	NG	2.5GBASE-T full duplex

Legend: NG: A connection is not possible

The following tables show SFP port and SFP+/SFP shared port when SFP-T is used.

Table 20-5: Connection specifications (SFP-T used for SFP port and SFP+/SFP shared port)
Remote device		Settings on the Switch
Method	interface	Auto-negotiation
Fixed settings	10BASE-T half duplex	NG
	10BASE-T full duplex	NG
	100BASE-TX half duplex	NG
	100BASE-TX full duplex	NG
	1000BASE-T half duplex	NG
	1000BASE-T full duplex	NG
Auto-negotiation	10BASE-T half duplex	NG
	10BASE-T full duplex	NG
	10BASE-T Full and Half Duplex	NG
	100BASE-TX half duplex	NG
	100BASE-TX full duplex	NG
	100BASE-TX Full and Half Duplex	NG
	10BASE-T/100BASE-TX full duplex and half duplex	NG
	1000BASE-T half duplex	NG
	1000BASE-T full duplex	1000BASE-T full duplex
	1000BASE-T Full and Half Duplex	1000BASE-T full duplex
	10BASE-T/100BASE-TX/1000BASE-T full duplex and half duplex	1000BASE-T full duplex

Legend: NG: A connection is not possible

(3) Auto MDI/MDIX function

The Auto MDI/MDIX function automatically switches MDI and MDI-X. The functionality enables communication via either a crossover cable or a straight cable, and is available only when auto-negotiation is used. This functionality supported only during auto-negotiation. It is MDI-X when full duplex is fixed. The following table describes the MDI and MDI-X pin mappings.

TABLE 20-6 MDI/MDI-X pin mapping
RJ45 Pin No.	MDI			MDI-X
RJ45 Pin No.	1000BASE-T 2.5GBASE-T ^#1	100BASE-TX^#2	10BASE-T^#2	1000BASE-T 2.5GBASE-T ^#1	100BASE-TX^#2	10BASE-T^#2
1	BI_DA+	TD+	TD+	BI_DB+	RD+	RD+
2	BI_DA-	TD-	TD-	BI_DB-	RD-	RD-
3	BI_DB+	RD+	RD+	BI_DA+	TD+	TD+
4	BI_DC+	Unused	Unused	BI_DD+	Unused	Unused
5	BI_DC-	Unused	Unused	BI_DD-	Unused	Unused
6	BI_DB-	RD-	RD-	BI_DA-	TD-	TD-
7	BI_DD+	Unused	Unused	BI_DC+	Unused	Unused
8	BI_DD-	Unused	Unused	BI_DC-	Unused	Unused

#1: In 1000BASE-T and 2.5GBASE-T, all 8-pins are transmitted and received in simultaneous bidirectional (bi-direction) communication, so the signal naming differs (BI_Dx: bidirectional data signal).
#2: For the 10BASE-T and 100BASE-TX cables, separate signal lines are used for sending (TD) and reception (RD).

(4) Downshift function

When auto-negotiation is set, the down-shift function disables the fastest speed advertised by auto-negotiation when the link connection cannot be established at the optimum connection operation (fastest line speed) determined by auto-negotiation (for example, when auto-negotiation is set to the optimum connection operation, but 1000BASE-T cannot connect at 1000Mbit/s due to poor transmission quality, etc.), and then tries the link connection at the fastest speed.

(a) Line speed change order

If the link cannot be connected after auto-negotiation is completed, the line speed advertised by auto-negotiation is reduced in the order of Phase 1, Phase 2,.... If the link connection is not possible even if the line speed becomes the lowest, return to phase 1 and perform the downshift repeatedly. The following table shows the order of changing the line speed for each port type.

Table 20-7: Sequence of changing line speeds (10BASE-T/100BASE-TX/1000BASE-T)
Phase	Parameter setting details of the configuration command speed #1
Phase	auto	auto 10 100 1000	auto 10 100	auto 1000^#2 or auto 100^#2 or auto 10^#2
1	10 100 1000	10 100 1000	10 100	-
2	10 100	10 100	10	-
3	10	10	-	-

Legend:--: Do not perform downshift operation

#1: The value indicates the line speed. Units are Mbit/s.

#2: If you do not want to perform downshift operation, make this setting.

Table 20-8: Sequence of changing line speeds (100BASE-TX/1000BASE-T/2.5GBASE-T)
Phase	Parameter setting details of the configuration command speed #1
Phase	auto or auto 100 1000 2500^#2	auto 100 1000^#2	auto 1000 2500	auto 2500^#3 or auto 1000^#3 or auto 100^#3
1	1000 2500	1000	1000 2500	-
2	1000	-	1000	-

Legend:--: Do not perform downshift operation

#1: The value indicates the line speed. Units are Mbit/s.

#2: Downshift to 100Mbit/s is not supported.

#3: If you do not want to perform downshift operation, make this setting.

(5) Notes on connection

Make sure that the transmission speed and the duplex mode (full or half) settings on the local and remote devices are the same.

If these settings on the devices are different, communication might stop. If communication stops, execute the inactivate command, and then execute the activate command for the relevant ports.
Refer to the "Hardware Instruction Manual" for the cable to be used.
A full-duplex interface is implemented by not using collision detection and loopback functions. Therefore, to use a 10BASE-T or 100BASE-TX connection for a full-duplex interface, always make sure that the remote port is set as a full-duplex interface.