20101231

Ring out the old? Serial Consoles STILL going strong!

The last couple of weeks have been very busy, helping acquire a small company for a customer. The majority of my role included assessing, and then upgrading the network gear, as well as helping with the various server gear.

After the initial assessment, I installed Conserver on a local host, and I re-deployed a Cisco 3640 with a pair of NM-32A asynch modules. The serial consoles were VITAL to take over network gear for which the previous administrator could offer no admin credentials. Some of the network gear was also equipment with older operating software, which I had little experience with, so I needed to engage technical help from the equipment vendor. The first two questions were always "Can we do a remote desktop conference?" and "Do you have access to the serial console?" It's always nice to be able to answer "yes" to both questions. There is also some comfort in knowing that Conserver will be logging the session, so you can look back over the logs after the fact to review what happened.

During this session, I was also working with some Juniper gear, and I'm REALLY happy that Juniper also use the RJ45 wiring schema that Cisco uses. I'm a big fan of that symmetrical wiring format.

It's worth noting that SUN Microsystems newer machines (starting back with the Netra T-1) have also used this wiring schema for their TTYs0, and some Lantronix console servers have also used the wiring schema. Opengear has made this wiring schema an option for many of their products, and it is becoming the primary wiring format for some of their newest products. This makes hooking up the majority of the equipment that I work simple, AND it gives me some flexibility to choose different hardware vendors with confidence that they will drop into my existing infrastructure nicely.

Finally, I wanted to point out that serial port capability is also still being built into embedded processors! I've had some time to hack with the ATMEL processors used in the Arduino family of development boards. One port is normally integrated with a bootloader and connected to a USB interface (typically with an FTDI interface chip) to make it easy to talk to the processor. However, these 3.3-to-5 volt "TTL" interfaces can also be tied to an RS-232 interface chip when the ATMEL chip is plugged into an embedded system. (As an alternative, there is another pair of pins which can be a data-only 9600 bps (max) serial port to communicate between the ATMEL chip an another device. And the larger ATMEGA actually has 3 extra serial ports available!) My newest project is to make a small processor which can communicate via a serial interface to another system.

As we enter 2011, the venerable RS-232 serial interface lives on. I wish you all health and happiness, and hopefully a bit of prosperity as well.

         -Z-

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