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CB-RE and RCB Interface Cable and Wire Specifications for MX Series Routers

Table 1 lists the specifications for the cables that connect to management ports and the wires that connect to the alarm relay contacts.


In routers where the Routing Engine (RE) and Control Board (CB) are integrated into a single board, a CB-RE is known as Routing and Control Board (RCB). The RCB is a single FRU that provides RE and CB functionality.

Table 1: Cable and Wire Specifications for Routing Engine and RCB Management and Alarm Interfaces


Cable Specification

Maximum Length

Router Receptacle

Routing Engine console or auxiliary interface

RS-232 (EIA-232) serial cable

1.83 m

RJ-45 socket

Routing Engine Ethernet interface

Category 5 cable or equivalent suitable for 100Base-T operation

100 m

RJ-45 autosensing

Alarm relay contacts

Wire with gauge between 28-AWG and 14-AWG (0.08 and 2.08 mm2)



We no longer include the RJ-45 console cable with the DB-9 adapter as part of the device package. If the console cable and adapter are not included in your device package, or if you need a different type of adapter, you can order the following separately:

  • RJ-45 to DB-9 adapter (JNP-CBL-RJ45-DB9)

  • RJ-45 to USB-A adapter (JNP-CBL-RJ45-USBA)

  • RJ-45 to USB-C adapter (JNP-CBL-RJ45-USBC)

If you want to use RJ-45 to USB-A or RJ-45 to USB-C adapter you must have X64 (64-Bit) Virtual COM port (VCP) driver installed on your PC. See, to download the driver.