What is a Console Terminal Server?

Console Terminal Servers are called on to perform a wide variety of duties in large data centers, but the most common Console Terminal Server application is to provide remote communication with console ports on network devices.  In out-of-band access applications like this, the Console Terminal Server is essentially serves as an alternate path between tech support personnel and console ports on network devices.

When an important network element crashes and interrupts normal communication, the Console Terminal Server can furnish techs with a substitute gateway to console ports on affected devices, allowing problems at remote sites to be corrected without a service call.  Instead of hopping into the service van and visiting the equipment site in person, support personnel can establish an out-of-band connection to the Console Terminal Server, and then immediately access console ports in order to correct configuration problems, re-load corrupted routing tables or perform other troubleshooting tasks to bring network communication back on line.

How Do I Communicate with the Console Terminal Server?

The key to a successful Console Terminal Server implementation is often the means selected for out-of-band communication with the Console Terminal Server.  The most commonly encountered avenues for out-of-band access are secondary network, cellular modem and surprisingly, the good old-fashioned dial-up modem.  While a secondary network connection is probably the ideal solution, there are many situations where a secondary, maintenance network just isn’t feasible.

For example, in cases where the network equipment site is extremely remote or hard-to-get-to, even access via primary network might be impractical, due the expense of running network cables to the site.  In applications like this, were a small LAN is located at a distant site, isolated from normal network communication, either dial-up or cellular communication might provide the best solution.  In other cases, where the equipment site includes network access but lacks a dial-up phone line, then it’s often more practical to communicate with the Console Terminal Server via cellular.  Generally speaking, the ideal solution for communication with the Console Terminal Server will often be dictated by the nature of the network equipment site itself, and the types of communication available onsite.

How Can I be Sure that the Console Terminal Server is Secure?

In most cases, a high quality Console Terminal Server will support an array of different security and authentication protocols, to ensure that only verified, recognized users with valid accounts are able access remote console ports.  In addition to password protection and IP address filtering, high-end Console Terminal Servers often support popular authentication protocols such as LDAP, Active Directory, Kerberos, RADIUS, TACACS+, DUO and RSA to help verify the identity of each user.  In order to protect communication with the Console Terminal Server from interception, FIPS 140-2 Cryptography and protocols such as HTTPS, SSHv2, SNMPv3 and Transport Layer Security (TLS) can be very useful in ensuring that data is hidden from unauthorized access.

In addition to blocking unauthorized users from accessing the Console Terminal Server, sometimes it’s also helpful to restrict the access of valid users, based on each user’s security level or qualifications.  In cases like this, a Console Terminal Server that allows administrators to set access privileges for each user account.  This allows you to limit each user to specific console ports and restrict access to potentially risky functions such as configuration capabilities.

What’s the Best Solution for My Out-of-Band Console Terminal Server Application?

When choosing a Console Terminal Server, the first step is to consider the nature of the site where the Console Terminal Server will be deployed.  As discussed above, the most important consideration is probably the types of communications options that are available at the equipment site.  To repeat, if the site allows handy access by primary and secondary network, cellular and dial-up, then almost any of these will work; but if there are limited access options, then you’ll need to figure out which available option will work for primary communication and which will work for out-of-band.

The type of power supply available on-site is also an important consideration, but fortunately, most decent Console Terminal Servers are available in both AC and DC Powered configurations.

Another thing to consider is the number of console ports on devices at the site that you’ll need access to.  In the case of small equipment installations or kiosks, you might only need access to four or five ports; while in larger data center applications, you might need out-of-band access to 30 or more ports.  Fortunately, this decision is made easy by the fact that most quality Console Terminal Server models are available in different sizes, ranging from simple four port units up to forty ports and beyond.

One important consideration that’s often overlooked is the quality, reputation and performance record of the Console Terminal Server.  Since the Console Terminal Server will be an important part of your network support program, it’s often a good idea to avoid inexpensive, cheaply built models, splurge a little bit and buy a brand that has a good reputation for reliability and durability and includes a wide range of features that will help you to custom tailor your Console Terminal Server to best fit your application.  There’s an old adage that, “A Console Terminal Server is only important when you need it.  Most of the time, it just sits in the rack collecting dust, but when you need it, you REALLY need it.”