Review: Lightwave Communications CS800

Product Review:

ConsoleServer 800
Lightwave Communications

Rating: Recommended


For the first product review of the new year, I’ll be taking a look at the
ConsoleServer 800 from Lightwave Communications. This is a 1U rackmountable
8-port serial console server, packed full of features.

Until I ran across the CS800, I’d never used a “dedicated” console server
before (e.g., one *designed* to be a console server). I’d always used
equipment such as a Lucent PortMaster or a Cisco AS5200 (designed to be
remote access servers with modems attached) with rigged-up serial connections
to the equipment I wanted to reach remotely. Unfortunately, doing it that
way had a few problems:

  • Lack of scrollback buffer to see crash/panic messages or console logs
  • Only one person at a time could access each device
  • Sometimes, rebooting the access server caused a BREAK signal to be
    sent – dropping Sun systems into OpenBoot
  • Only user/password access control; no fine-grained access restrictions
  • Then, in late 2001, I ran across
    Lightwave Communications
    . I’d used one of their other products before
    at my “day job” – the ServerSwitch, and had been very happy with it. I had a
    need for a serial console server for the SunHELP servers (and some other
    machines that sit in the same rack), so I took a look at the ConsoleServer
    800. The folks there were kind enough to send me a unit for review, as
    well as a ConsoleServer 3200 and a 2-port ServerSwitch.

    Product Design.

    The CS800 has a 1U (rackmountable) form factor, uses a standard power cord,
    and has RJ45 ports for serial cable connectors (as is now pretty much
    standard across the industry – this saves space on the console server end
    of things). All the ports are on the back, while the front has the product
    and company name/logo, with a backlit status-display LCD and some membrane
    “buttons” to control the LCD. Ports on the back, from left to right
    (see picture link below):

  • AC Power cord
  • Power Switch
  • Modem module
  • Ethernet
  • Console
  • Serial Ports (1-8)
  • Power Controller Serial (DB9)
  • The CS800 is available with -48VDC power supplies instead of AC, and the
    modem module is optional. I was not able to test the functionality of
    the modem module on my review unit, due to lack of an available phone

    First thing I really liked: The users manual and updated firmware for
    the CS800 are available from Lightwave’s FTP site. When I misplaced the manual, I just went to
    the FTP site, downloaded it again, and was ready to go (I later found the
    one that I had lost). Pinouts for all of the ports on the CS800 are detailed
    in the user manual, in case you want to “roll your own” RJ45-serial connectors
    instead of purchasing them from Lightwave along with the console server.
    Firmware upgrades on the CS800 are performed via TFTP over the network.

    First Use.

    My first use for the CS800 was setting up one of the new SunHELP servers,
    which went online in early November (yes, this review has taken a while to
    writeup and get online). Lightwave supplied plenty of RJ45-to-DB25 adapters
    (as shown in the picture), so all I had to do was connect a normal straight-
    wired Cat5 (cat3 would also work, as this is just 9600 baud serial) cable
    between the adapter and the RJ45 port on the back of the CS800.

    Interfacing to the CS800 can be done either through telnet, or a directly-
    attached serial console. I used a nullmodem connection between my SunBlade
    1000 and the CS800’s console port to do initial setup and TCP/IP configuration,
    then used it from then on through a telnet session on the local network.

    The front-panel LCD display can show either software version, port use
    status (showing what user is logged in either over the network or through
    direct-connect serial), or TCP/IP configuration information. This is
    toggled via the buttons on the front of the unit. The LCD is backlit and
    is very viewable (see pictures below).

    The CS800 also includes a “power controller” port, which is basically just
    another serial port, but with a DB9 connector. With the right cables, you
    can connect this to a normal device as well instead of a power controller
    serial connection, and use it just like the RJ45 device ports, making the
    CS800 into a 9-port console server.

    Something I didn’t like: The ethernet port (RJ45) on the CS800 is
    10baseT *only*. This is noted in the manual, which states that you *MUST*
    plug it into a 10baseT network connection, and that 10/100baseT autonegotiating
    ports on a hub or switch will *not* work. I tried and verified this fact
    with a Cisco Catalyst 1900 switch as well as a NetGear 10/100baseT switch;
    the network port only works when plugged into a 10baseT half-duplex link.
    This is a severe hindrance, as when I later put a CS800 into production use
    with the SunHELP servers, I had to daisy-chain it off of a 10baseT ethernet
    hub that was then plugged into the same 10/100 switch as the rest of the
    machines. Having to dedicate a 10baseT hub to correct a product limitation
    such as this is not good, when I suspect a 10/100baseT chipset (or at least
    one that can autonegotiate enough to tell a switch to go to 10baseT half-
    duplex) would not have been much more expensive than what was used.

    When logging into the CS800, you log in either as a normal user, or
    as the administrator. All access is authenticated; in fact, I could not
    find a way to give someone “free and open” access to the unit, which is
    a good feature. The Administrator only logs by telnetting to port 5000.
    This is another good feature, as Administrator access could be firewalled
    off from the Internet, for example, only allowing “normal” users to telnet
    to the server on port 23. The Administrator account is not able to access
    device ports; it is only used for creating and managing user accounts and
    system settings. Therefore, you have to create at least one user account
    in order to use the CS800 for its intended purpose. According to the manual,
    it is also not possible to obtain access to the administration functions
    via the modem connection – I’m guessing this is for security reasons.

    The CS800 does not have a Web-based interface like so many products these
    days; all interaction is done through a command line or a Curses-based
    “menu”; in either case, its straight text. After login (see links
    below for pictures of the various admin and user login, help, and
    device menus), you can press CONTROL-D to get the menu-based CURSES
    interface, or continue to use the line-by-line interface.

    Access Control.

    Unlike the process of using an access server as a console server
    device, the CS800 allows up to six concurrent people to be logged in,
    all viewing the same console output at the same time. Only one person
    can be fully interactive with the console, the rest can just “listen”,
    or watch the device. This allows a configuration where a tech support
    employee could watch console logs from a router or server, without having
    to worry about generating keystrokes or codes that could hang or stop the
    device in question. Each port has a 64-kilobyte scrollback buffer, and
    50 separate user accounts can be created.

    Each user account can have the following parameters:

  • User ID (login name)
  • Password
  • Maximum Number of Concurrent Logins
  • Allowed Ports
  • Clear Device Buffer (for scrollback)
  • Clear Screen After Commands
  • Being able to restrict a user to certain ports is very useful. After
    installing a CS800 with the SunHELP servers, I still had two (out of
    eight total) device ports free. I was able to connect them to a
    pair of servers at OnRamp, and add
    an “onramp” user account that only had access to those two ports.
    This allows OnRamp employees to have direct console access to their
    systems, but no access to my six devices. However, I can still walk
    up to the direct-attached serial terminal in the next rack over, or
    connect via telnet, and login with full access to the device ports
    that my systems are connected to. I mentioned before about other
    terminal servers generating unwanted BREAK signals; the CS800 is
    designed to only generate a BREAK when instructed; the default key
    sequence for this is ESC-B, which is fully customizable.

    Another thing I didnt like: When using the fancy CURSES-based
    menu interface, the cursor dissapears. This persists even after you
    exit a menu and connect directly to a device – making things such as
    text editing very painful without being able to see the cursor. This
    problem doesent exist when ONLY using the direct-command-line interface.
    Tested and replicated this problem using xterm and rxvt, as well as a
    genuine DEC VT510 terminal directly attached to the console port of
    the CS800.

    NOTE: (12/8/03) This problem has gone away in a later version of the
    CS800 firmware.

    Other than the ethernet requirements and dissapearing cursor problem
    (which will hopefully be fixed in a newer firmware release), I’ve never
    had a single problem with the CS800. Its never hung, locked up,
    spat out garbage, etc. I’ve got it connected to a pair of E250s, an
    AXi-based SPARC machine, two SunFire 280Rs, and a Netra T1 (Lightwave
    sells an inline RJ45-to-RJ45 adapter instead of an RJ45-DB25 adapter
    for devices such as the Netra T1/X1 and Cisco networking hardware that
    use an RJ45 console connection).

    Overall thoughts.

    I like it. A lot. So much that I now have one sitting permanently at
    the top of the rack of SunHELP equipment in downtown Austin. Its saved
    me a trip downtown (a six-mile drive) many times now in the past two months
    of service, and I wonder why I didnt get one sooner. The couple of limitations
    I found are easily worked around or ignored and not an impact on what users
    I need the CS800 for.

    I dont have a goofy “star” rating, but I will say that the CS800 is
    highly recommended. If you have a need for a good, quality serial
    console server, the CS800 will work great for you.

    Contact Lightwave
    for more information or to purchase a ConsoleServer 800.

    NOTE: (12/8/03) Since this review was originally published,
    Lightwave was acquired by Lantronix,
    and the CS800 has since been discontinued. It is still available from
    third-party resellers.

    Note: I also took a look at the ConsoleServer 3200, a 32-port version of
    the CS800. Differences between the two:

  • ConsoleServer 3200 has 32 ports, in a 4U form factor and bigger LCD
  • CS3200 allows up to 17 concurrent user sessions, versus 6 in the CS800
  • User sessions can be either telnet or direct-connect serial
  • Port configuration is changeable – system uses port cards and is not
  • Other than these differences, the CS800 and the CS3200 operate basically the
    same from an administration and end-user point of view.

    Bill Bradford

    January 24, 2001

    Product Pictures