Connection Of the Console Interface On Cisco ASR 920 Series Routers

During the use of the Cisco ASR-920-24SZ-M router, Moduletek Laboratory found that its console port differs from that of other Cisco devices—it adopts a USB-A physical form factor. This article details the correct connection method for the console port of Cisco ASR 920 series routers.

We first attempted to use a standard USB-to-DB9 serial cable, but the connection failed. Following the official installation manual, we also added an RJ45 adapter to a USB-to-RJ45 cable, converted it to a DB9 connector, and connected it to a terminal device—this also failed to establish console access.

According to the official installation manual, although the console port has a USB-A physical appearance, it is not a standard USB interface. Instead, it complies with the TIA/EIA-232F serial standard.

Figure 1 Interface Connection Failure Prompt

We found a technical sharing post about the console port of Cisco ASR 920 series routers on Cisco Community, which provides the correct cable pinout sequence.

Figure 2 Cable Pinout Arrangement

We then made a dedicated console cable following this standard pinout:

Prepare a common Micro USB cable, cut off the Micro USB connector at one end, and strip the outer insulation. Four internal copper wires are exposed, colored red, white, green, and black.

Figure 3 USB Cable with One End Cut Off

Arrange the four copper wires strictly according to the standard pinout sequence, insert them into the corresponding positions of the RJ45 crystal head, and crimp firmly with a crimping tool. A clear "click" sound indicates successful crimping.

Figure 4 Wire Insertion into RJ45 Crystal Head

After the custom console cable is completed, use an RJ45-to-DB9 female adapter to connect to the router’s console port. Alternatively, it can be matched with a standard RJ45-to-DB9 serial cable.