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Conference netcad::hub_mgnt

Title:	DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:	Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:	NETCAD::COLELLADT

Created:	Wed Nov 13 1991
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	4455
Total number of notes:	16761

291.0. "DECbridge 90/ OSF1 ccr: Retry limit exceeded" by DC101::COLE (ADEG Programs Team/Greenbelt,Md) Thu Jul 01 1993 12:51

	Config questions:

	I'm adding a DECbridge 90 to a DEChub 90 currently
	containing several 90T repeaters.  The backbone connection
	is thinwire, currently connected to the DEChub 90 backplane.
	I assume I remove this thinwire connection from the backplane
	and connect it to the front of the DECbridge 90 with a
	T-connector and terminator (?) and also put a thinwire
	terminator on the DEChub 90 backplane thingwire connection ?



	This configuration appears to work, but now I get the following
	when I attempt to connect to the bridge after about 10 seconds:


	# /usr/sbin/ccr wgb
	ccr: Remote console reserved
	DECbridge 90 V1.14  08-00-2B-27-7A-0F ) 1991 Digital Equipment Corp
	FPROM V3.1 )1991,93 Digital Equip Corp 5-APR-93

	DECbridge>
	ccr: Retry limit exceeded

	ccr: Remote console released
	#


	This is an AOSF system DEC OSF/1 T1.3-3 (Rev. 59.2);

    Implementation                    =
       {
          [
             Type = . . . . . DECnet/OSI for OSF/1
             Implementation = "DECnet/OSI for DEC OSF/1 AXP T1.1-2 DECnet-OSI k
it built: Thu Jun 03 20:46:28 EDT 1993"
         


	
	ccr appears to work okay when connecting to a DS700 terminal server
	it doesn't terminate the connection but does give the 
	
	ccr: Retry limit exceeded

	message after logging out of the terminal server.


	Anyone have any ideas ?


	thanks,


	...larry

T.R	Title	User	Personal Name	Date	Lines
291.1		PRNSYS::LOMICKAJ	Jeffrey A. Lomicka	`Tue Jul 06 1993 14:18`	44
	> I'm adding a DECbridge 90 to a DEChub 90 currently > containing several 90T repeaters. The backbone connection > is thinwire, currently connected to the DEChub 90 backplane. > I assume I remove this thinwire connection from the backplane > and connect it to the front of the DECbridge 90 with a > T-connector and terminator (?) and also put a thinwire > terminator on the DEChub 90 backplane thingwire connection ? This is correct. > This configuration appears to work, but now I get the following > when I attempt to connect to the bridge after about 10 seconds: > > > # /usr/sbin/ccr wgb > ccr: Remote console reserved > DECbridge 90 V1.14 08-00-2B-27-7A-0F ) 1991 Digital Equipment Corp > FPROM V3.1 )1991,93 Digital Equip Corp 5-APR-93 > > DECbridge> > ccr: Retry limit exceeded > > ccr: Remote console released > # Argh. Ultrix has a history of outstandingly bad implementations of "ccr". They get it to just barely work with a terminal server, and then ship it. The essential "ccr" difference between a DECbridge 90 and a terminal server is that the terminal server uses hardware CRC computation, and can act on a console request in about 7ms, round trip. The DECbridge 90 has to compute the CRC is software on a slow processor (because the bridge preserves CRC on incoming messages), and therefore takes about 20ms to turn around a message. In previous versions of Ultrix, "ccr" choked horribly on the extra delay. I suspect it still does. It tends to retry every 12ms, even though THE SPEC FOR MOP RECOMMENDS 100ms!!! The result is that the bridge receives (and replies to) a lot of duplicate messages. I suspect that Ultrix is responding badly to the duplicate responses. I don't know how to fix it. I don't know who in Ultrix to talk to about it. My best suggestion is to use a DECserver90L+ for your MOP connection, or if there is a VMS system nearby, use that.
291.2	OSF/1 not Ultrix	DC101::COLE	ADEG Programs Team/Greenbelt,Md	`Tue Jul 06 1993 14:29`	23
	>>Argh. Ultrix has a history of outstandingly bad implementations of "ccr". T>hey get it to just barely work with a terminal server, and then ship i>t. >I don't know how to fix it. I don't know who in Ultrix to talk to about >it. My best suggestion is to use a DECserver90L+ for your MOP >connection, or if there is a VMS system nearby, use that. This is OSF/1 not Ultrix, although I bet the code is the same. This is also a 100% OSF/1 shop, no VMS around (the Govt doesn't buy VMS systems anymore). Who own responsibliity for ccr ? thanks, ...larry
291.3		TOOK::D_NELSON	Dave Nelson LKG1-3/A11 226-5358	`Tue Jul 06 1993 14:35`	7
	RE: .2 > Who own responsibliity for ccr ? You might start with Matt Thomas...