MX480 Switch Control Boards

SCB-MX Description

The MX Switch Control Board (SCB-MX) provides control plane functions, chassis management functions, and switch plane functions for MX960, MX480, and MX240 routers. It is also a carrier for the Routing Engine which installs directly into a slot on the SCB-MX. See Figure 1.

Software release	Junos OS Release 12.3 R1 and later Name in CLI: `SCB`
SCB-MX Functions	Powers on and powers off DPCs, FPCs, and MPCs. Controls clocking, system resets, and booting. Monitors and controls system functions, including fan speed, board power status, power distribution module status and control, and the craft interface Provides Ethernet connectivity to all processors in the chassis for control plane communications. Provides bandwidth of up to 160 Gbps per slot with redundant fabric support. Provides interconnections to all the DPCs, FPCs, and MPCs within the chassis through the switch fabrics integrated into the SCB-MX.
SCB-MX Components	Control Board and Routing Engine (CB-RE) mastership mechanism. External clock interface—Allows BITS or GPS clock source input to the centralized timing circuit, or allows centralized timing to be output to BITS or GPS. Switch fabric—Provides switching functions for MPCs. 1000Base-T Ethernet controller—Provides a 1 Gbps Ethernet link between the Routing Engines. Power circuits for the Routing Engine and the SCBE2-MX. LEDs—Provide status of the SCBE2-MX and the clocking interface.
SCB-MX Slot Numbers	For the MX960: You can install up to three SCB-MXs in the MX960 chassis for a total of six switch fabrics and six fabric planes. The SCB-MXs install vertically into the front of the MX960 chassis in the slots labeled `0`, `1`, and `2/6`. Note: On the MX960, either a SCB-MX or a DPC can be plugged into slot 8. A third SCB-MX is used only for switch fabric redundancy. Therefore, if an application does not require switch fabric redundancy, a DPC can be used in slot 8. For the MX480 and MX240 routers: You can install one or two SCB-MXs in the MX240 and MX480 for a total of four switch fabrics and eight fabric planes. The SCB-MX installs horizontally into the front of the chassis in the slots labeled 0 and 1. If any slots are empty, you must install a blank panel.
Weight and Dimensions	Weight: 9.6 lb (4.4 kg) (with Routing Engine installed) Width: 17 in (43.2 cm) Depth: 22 in (55.9 cm) Height: 1.25 in (3.2 cm) height.
SCB-MX Fabric Planes and Redundancy	For MX960 routers: Each SCB-MX provides two switch fabric planes for packet forwarding among the DPCs and MPCs in the MX960. The MX960 chassis may contain up to three SCB-MX's Therefore, six fabric planes are available. The MX960 provides 2 + 1 SCB-MX redundancy when used with DPC line cards. In redundant fabric mode, four fabric planes from the first two SCB-MX’s will be in Active mode, and two fabric planes from the third SCB-MX will be in Spare mode. In a non-redundant fabric mode, all six fabric planes will be in Active mode to increase fabric bandwidth. SCB-MXs installed in slots `0` and `1` provide non-redundant fabric connections. An SCB-MX installed in slot `2/6`, in conjunction with SCB-MXs in slots `0` and `1`, provides redundant fabrics, but the Routing Engine installed on it receives no power and provides no additional routing functions. If no SCB-MX is installed in slot `2/6`, you must install a blank panel in the slot. For MX240 and MX480 routers: Each fabric ASIC is configured in virtual plane mode, where two virtual planes exist on one fabric ASIC. This means that the MX240 and MX480 require only a single SCB-MX to provide line rate throughput, and an additional SCB-MX to provide 1 + 1 SCB redundancy. In redundant fabric mode, four virtual planes from the first SCB-MX will be in Active mode, and four virtual planes from the second SCB-MX will be in Spare mode. In a non-redundant fabric mode, all eight virtual planes will be in Active mode to provide the maximum fabric bandwidth.
Maximum Power Requirements	SCB-MX (applies to MX240, MX480, and MX960) 185 W at 55° C 160 W at 40° C 155 W at 25° C

SCB-MX LEDs

Three LEDs on the SCB indicate the status of the SCB. The LEDs, labeled FABRIC ACTIVE, FABRIC ONLY, and OK/FAIL, are located directly on the SCB. Table 1 describes the functions of the SCB LEDs.

Table 1: SCB-MX LEDs

Label	Color	State	Description
`FABRIC ACTIVE`	Green	On steadily	Fabric is in active mode.
`FABRIC ONLY`	Green	On steadily	SCB-MX operates in fabric-only mode.
`FABRIC ONLY`	–	Off	SCB-MX operates in fabric/control board mode.
`OK/FAIL`	Green	On steadily	SCB-MX is online.
	Red	On steadily	SCB-MX has failed.
	–	Off	SCB-MX is offline.

SCB-MX Fabric Plane Scale and Redundancy

Each of the fabric planes on the SCB-MX is able to process 20 Gbps of bandwidth. The MX240 and MX480 use eight fabric planes across two SCB-MXs, whereas the MX960 uses six fabric planes across three SCB-MX’s˙. Because of the fabric plane virtualization, the aggregate fabric bandwidth between the MX240, MX480, and MX960 is different. Refer to Table 2.

Table 2: SCB-MX Fabric Plane Scale and Redundancy Assuming Four PFEs per FPC

SCB-MX	MX240	MX480	MX960
PFEs	12	24	48
SCBs	2	2	3
Switch Fabrics	4	4	6
Fabric Planes	8	8	6
Spare Planes	4 (1+1 SCB-MX redundancy)	4 (1+1 SCB-MX redundancy)	2 (2+1 SCB-MX redundancy)
Fabric Bandwidth Per Slot	160 Gbps	160 Gbps	120 Gbps

Supported Routing Engines

The SCB-MX supports the following routing engines (REs):

SCBE-MX Description

The MX Enhanced Switch Control Board (SCBE-MX) for MX960, MX480, and MX240 routers serves the carrier Ethernet services router and carrier Ethernet transport markets that require higher-capacity traffic support, demanding greater interface density (slot and capacity scale), as well as improved services. The SCBE-MX provides:

160 Gbps/slot bandwidth with redundant fabric support, and improved fabric performance by using the next-generation fabric (XF) chip
A central clocking module and a centralized clocking architecture that supports clock cleanup and distribution. The Stratum 3 clock module performs clock monitoring, filtering, and holdover in a centralized chassis location
Full performance with fabric redundancy for higher capacity line cards such as 16x10GE and MPC3

The Routing Engine installs directly into a slot on the SCBE-MX (see Figure 2).

Table 3 lists the maximum number of SCBE-MXs you can install in the MX chassis, the corresponding slot labels, and the backup slot used for redundancy. If any slots are empty, you must install a blank panel.

Table 3: SCBE-MX Specifications

Chassis	Maximum SCBE-MXs	Slot Labels	Backup Slot
MX960	3	`0`, `1`, and `2`	`2`
MX480	2	0 and 1	1
MX240	2	0 and 1	1

Routing Engines and MPCs for the SCBE-MX

The SCBE-MX supports the routing engines and MPCs in Table 4.

Table 4: Supported Routing Engines and MPCs for the SCBE-MX

Supported Routing Engines	Supported MPCs
RE-S-1300 RE-S-1800 (all variants) RE-S-2000	MPC3e MPC3e MPC3e

Supported Routing Engines

Supported MPCs

RE-S-1300

RE-S-1800 (all variants)

RE-S-2000

MPC3e

SCBE-MX LEDs

The FABRIC ACTIVE, FABRIC ONLY, and OK/FAIL LEDs indicate the status of the SCBE-MX. The BITS, GPS, and UTI LEDs (next to the EXT CLK port) indicate the status of the respective clocking interface. Table 5 describes the behavior of the SCBE-MX LEDs.

Table 5: SCBE-MX LEDs

Label	Color	State	Description
`FABRIC ACTIVE`	Green	On steadily	Fabric is in active mode.
`FABRIC ONLY`	Green	On steadily	SCBE-MX operates in fabric-only mode.
`FABRIC ONLY`	–	Off	SCBE-MX operates in fabric/control board mode.
`OK/FAIL`	Green	On steadily	SCBE-MX is online.
	Red	On steadily	SCBE-MX has failed.
	–	Off	SCBE-MX is offline.
	Red	On steadily	GPS clocking interface has failed.
	–	Off	GPS clocking interface is offline.
Note: The LEDs `BITS`, `GPS`, and `UTI` are not currently supported.
`BITS`	Green	On steadily	Building-integrated timing supply (BITS) clocking interface is active.
	Red	On steadily	BITS clocking interface has failed.
	–	Off	BITS clocking interface is offline.
`GPS`	Green	On steadily	Global positioning system (GPS) clocking interface is active.
	Red	On steadily	GPS clocking interface has failed.
	–	Off	GPS clocking interface is offline.
`UTI`	Green	On steadily	Universal Timing Interface (UTI) clocking interface is active.
	Red	On steadily	UTI clocking interface has failed.
	–	Off	UTI clocking interface is offline.

SCBE2-MX Description

The MX Enhanced Switch Control Board (SCBE2-MX) serves the carrier Ethernet services router and carrier Ethernet transport markets that require higher-capacity traffic support, demanding greater interface density (slot and capacity scale) as well as improved services. The SCBE-MX is supported on MX960, MX480, and MX240 routers.

The SCBE2-MX is installed vertically in the MX960 chassis and horizontally in the MX480 and MX240 chassis. The routing engine is installed directly into a slot on the SCBE2-MX (see Figure 3).

Software release	Junos OS Release 13.3 R1 and later Name in CLI: `SCBE2`
Requirements	For proper cooling, you must install MX-series high-capacity fan trays in the MX chassis. Additionally, for the MX960, you must install a high-capacity filter tray.
SCBE2-MX Features	Provides improved fabric performance for high-capacity line cards using the third generation fabric XF2 chip. Provides bandwidth of up to 340 Gbps per slot with redundant fabric support and 480 Gbps per slot without redundant fabric support. Provides a central clocking module and a centralized clocking architecture that supports clock cleanup and distribution. The Stratum 3 clock module performs clock monitoring, filtering, and holdover at a centralized chassis location. Supports dynamic multicast replication. Supports GRES. Supports MPC line cards. Does not support DPCs. Allows you to configure the system such that one SCBE2-MX supports a GPS interface, and the other SCBE2-MX supports a BITS interface. Provides support for cross-coupling of clock input. This requires an enhanced midplane: MX960—CHAS-BP3-MX960-S MX480—CHAS-BP3-MX480-S MX240—CHAS-BP3-MX240-S
SCBE2-MX Components	Control Board and Routing Engine (CB-RE) mastership mechanism. External clock interface—Allows BITS or GPS clock source input to the centralized timing circuit, or allows centralized timing to be output to BITS or GPS. Switch fabric—Provides switching functions for MPCs. 1000Base-T Ethernet controller—Provides a 1 Gbps Ethernet link between the Routing Engines. Power circuits for the Routing Engine and the SCBE2-MX. LEDs—Provide status of the SCBE2-MX and the clocking interface.
SCBE2-MX Slots	For the MX960: You can install up to three SCBE2-MX’s in the MX960 router chassis. SCBE2-MX’s are installed vertically into the front of the MX960 chassis in the slots labeled `0`, `1`, and `2`. If any slots are empty, you must install a blank panel. The two SCBE2-MX’s residing in slot 6 and slot 7 of the MX960 chassis provide both control and switch fabric features, while the third SCBE2-MX residing in slot 8 of the chassis (hybrid slot) will only do fabric functions. For the MX480 and MX240 routers: You can install either one or two SCBE2-MX’s in the MX480 and MX240 router chassis. SCBE2-MX’s are installed horizontally into the front of the MX480 and MX240 chassis in the slots labeled 0 and 1. If any slots are empty, you must install a blank panel.
SCBE2-MX Fabric Planes and Redundancy	For the MX960: Each SCBE2-MX provides two switch fabric planes for packet forwarding among the MPCs in the MX960. The MX960 chassis may contain up to three SCBE2-MX's Therefore, six fabric planes are available. Three SCBE2-MX’s are required for 2 + 1 redundancy. In redundant fabric mode, four fabric planes from the first two SCBE2-MX’s will be in Active mode, and two fabric planes from the third SCBE2-MX will be in Spare mode. In a non-redundant fabric mode, all six fabric planes will be in Active mode to increase fabric bandwidth. For the MX240 and MX480 routers: Each SCBE2-MX provides four switch fabric planes for packet forwarding among the MPCs in the MX480 and MX240 chassis. The MX480 and MX240 routers contain a maximum of two SCBE2-MX’s. Therefore, eight logical planes are available. Two SCBE2-MX’s are required for 1 + 1 redundancy. In redundant fabric mode, four fabric planes from the first SCBE2-MX will be in Active mode, and four fabric planes from the second SCBE2-MX will be in Spare mode. In a non-redundant fabric mode, all eight fabric planes will be in Active mode to provide increased fabric bandwidth. Each fabric ASIC is configured in virtual plane mode, where two virtual planes exist on one fabric ASIC.
Weight and Dimensions	Weight: 9.6 lb (4.4 kg) (with Routing Engine installed) Width: 17 in (43.2 cm) Depth: 22 in (55.9 cm) Height: 1.25 in (3.2 cm) height.
Maximum Power Requirements	SCBE2-MX (applies to MX240, MX480, and MX960) 185 W at 55° C 160 W at 40° C 155 W at 25° C
LEDs	`FABRIC ACTIVE`, `FABRIC ONLY`, and `OK/FAIL` LEDs indicate the status of the SCBE2-MX. The `BITS`, `GPS`, and `UTI` LEDs, located next to the `EXT CLK` port, indicate the status of the respective clocking interface. The `LINK` LED located next to the two Ethernet ports, indicate the status of the respective SFP+ interface. For more information about the SCBE2-MX LEDs, see SCBE2-MX LEDs.

SCBE2-MX Interoperability with Existing Hardware

SCBE2 Operating Mode	MX240/480/960	Supported
Enhanced IP/Enhanced Ethernet Mode Only	DPC/MS-DPC	No
	MS-MPC	Yes
	MPC1	Yes
	MPC2	Yes
	MPC3	Yes
	MPC4	Yes
	MPC2-NG	Yes
	MPC3-NG	Yes
	16x10GE MPC	Yes
	MPC5	Yes
	MPC6	No
	MPC7 (480 Gbps)	Yes
	MPC8 (960 Gbps)	No
	MPC9 (1.6 Tbps)	No
Routing Engines	RE-S-1300(EOLed) RE-S-2000 (EOLed) RE-S-1800 (all variants) RE-S-X6 (all variants)	yes yes yes yes

SCBE2-MX LEDs

FABRIC ACTIVE, FABRIC ONLY, and OK/FAIL LEDs indicate the status of the SCBE2-MX. The BITS, GPS, and UTI LEDs, located next to the EXT CLK port, indicate the status of the respective clocking interface. The LINK LED located next to the two Ethernet ports, indicate the status of the respective SFP+ interface. Table 6 describes the functions of the SCBE2-MX LEDs.

Table 6: SCBE2-MX LEDs

Label	Color	State	Description
`FABRIC ACTIVE`	Green	On steadily	Fabric is in active mode.
`FABRIC ONLY`	Green	On steadily	SCBE2-MX operates in fabric-only mode.
`FABRIC ONLY`	–	Off	SCBE2-MX operates in fabric or control-board mode.
`OK/FAIL`	Green	On steadily	SCBE2-MX is online.
	Red	On steadily	SCBE2-MX has failed.
	–	Off	SCBE2-MX is offline.
`BITS`	Green	On steadily	Building-integrated timing supply (BITS) clocking interface is active.
	Red	On steadily	BITS clocking interface has failed.
	–	Off	BITS clocking interface is offline.
`GPS`	Green	On steadily	Global positioning system (GPS) clocking interface is active.
	Red	On steadily	GPS clocking interface has failed.
	–	Off	GPS clocking interface is offline.
`UTI`	Green	On steadily	Universal Timing Interface (UTI) clocking interface is active.
	Red	On steadily	UTI clocking interface has failed.
	–	Off	UTI clocking interface is offline.
`LINK`	Green	On steadily	Port is enabled and link is established.
`LINK`	–	Off	Port is disabled or no link is established.

ON THIS PAGE

MX480 Switch Control Boards

SCB-MX Description

SCB-MX LEDs

SCB-MX Fabric Plane Scale and Redundancy

Supported Routing Engines

See also

SCBE-MX Description

Routing Engines and MPCs for the SCBE-MX

SCBE-MX LEDs

SCBE2-MX Description

SCBE2-MX Interoperability with Existing Hardware

SCBE2-MX LEDs

Related Documentation