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Zonker Harris Zonker.Harris@bigbandnet.com
Wed, 25 May 2005 08:55:29 -0700 (PDT)
First off; An ASM!! Oh My GOD! :-P (I declared the End Of Life on that during my days at Cisco, in the early 90's! Lots of warts on that unit! Save your pennies, and look for something better, ASAP! :-| OK, now, let me clarify; 1) Which part of Canada are you from? ;-) 2) PolyCentre is making the reverse-TCP connections to the ASM, and the ASM is making the physical serial connection with the RJ-11 jacks to your hosts, yes? 3) You (or your users) then connect to the Poly Centre in order to communicate with the consoles (through the ASM), have I got that right so far? If so, then Conserver would essentially replace the Poly Centre function, the reverse-TCP sessions would be up all the time (and logging anything coming into the serial ports on the ASM). The ASM should be replaced in this function, since the unit has a SEVERE problem passing LOTS of data at once. While capable (even in the mid-90's) of being a 112-port terminal server, it's top port speed was 38.4 Kbps, but the bigger issues were in Hardware Flow Control, and 'busy' ports... With the 6-wire interface used in the RJ-11, the Cisco needed one lead for ground, and so the decision was made to eliminate the ability for the ASM to tell the attached device to hold it's data. (They determined that they could process data coming into the ASM as fast as a user could type, so they didn't need to be able to say "Whoa!"...) They *did*, however, keep the hardware handshake lead, so they could tell when an attached modem was on-line. As for port speed, if you have 8 ports, configured for 9.6 Kbps, all getting data in at 'full-rate', your ASM is maxed out...if a 9th port starts getting some characters, everything slows down, buffers start to fill, memory leaks, data is lost, and (eventually) the unit will crash and reboot. If the ports are configured for 19.2 Kbps, you only get 4 active sessions at once, and if you run at 38.8, you only get two at a time. Trust me. :-) I don't recall if the unit sent Serial BREAK. It was early in Sun's life, and I wasn't paying attention to that when I did the other testing. My guess is, that it DOES send break, too. Bet to replace the ASM with something Sun Safe. (See my BREAK testing pages for more info. http://www.conserver.com/consoles/BREAK-off/breakoff.html You can use ACLs on Cisco gear (and there are similar access controls on most Console Servers these days), so that the Conserver host, and perhaps a few other trusted hosts, would be the only addresses allowed to connect to the Console Server(s). The "portbase" argument is which TCP port Conserver will start using when it's counting the serial 'ports' on each type of console server... In the Cisco world, the serial ports are usually found at TCP port 2000 + n, where 'n' is the number of the async line. (i.e., line #7 is at TCP 2007) In the Cyclades world, the calculation is 7000 + n... So, for Cisco units, the 'portbase' is typically going to be 2000, and for Cyclades, 'portbase' would typically be 7000. (In many cases, you *CAN* change that base port number on the Console Server as well, in case you want to hide your ports some non-standard number...if you change it on the console servers, you would also need to change the portbase number in the Conserver config as well.) From my main page (www.conserver.com/consoles/), look in the Useful URLs section, and check out the Linux Documentation Project links...Sections 4-6 are very useful for configuring the BIOS, Boot Loader, and GETTY configs for various machines, and may be of help with your Debian PC. :-) Regards, -Z-