Patch-ID# 103395-01 Keywords: bsc rje bad crc Synopsis: SunLink BSC RJE 6.0: Frames with bad CRC not discarded Date: May/08/96 Solaris Release: 1.x SunOS release: 4.1.1, 4.1.2, 4.1.3 Unbundled Product: SunLink BSC RJE Unbundled Release: 6.0 BugId's fixed with this patch: 1190997 Changes incorporated in this version: 1190997 Relevant Architectures: sparc Patches accumulated and obsoleted by this patch: Patches which conflict with this patch: Patches required with this patch: Obsoleted by: Files included with this patch: sunlink/bscrje/sys/sun4/OBJ/zs_bsctables.o Problem Description: (Revision 01) ------------- 1190997: Frames with bad CRC not discarded The BSC driver mishandles an error from a noisy line for a transparent intermediate block. A DLE character is mangled by noise, causing an ITB to be missed. But when the driver sees the next STX it stops reading the line and sends a NAK. When it resumes reading it picks up the second half of the block and NAKs it also, for a BCC error. The host retransmitted for each NAK, resulting in one too many copies of the block arriving. The BSC driver has been modified to allow control characters in text blocks, and let the BCC catch any errors at the end of the entire block. Page 17 of GA27-3004-2 (IBM BSC General Info) says: "Any station receiving a control character within a text block treats the control character or sequence as data and waits for the BCC to detect a possible error. If an error is detected, normal recovery procedures are used. If no error is detected, the transmission is treated as valid data." -------------------------------- Patch Installation Instructions: -------------------------------- Login as root for this procedure. Since this procedure is rebuilding the kernel, please take all necessary precautions, such as backing up the system first. 1. create a temporary directory. copy the patch into your directory. cd to the directory: # cd 2. Save the previous versions: # mv /usr/sunlink/bscrje/sys/sun4/OBJ/zs_bsctables.o \ /usr/sunlink/bscrje/sys/sun4/OBJ/zs_bsctables.o.orig 3. Copy the files in the patch: # cp /sun4/sunlink/bscrje/sys/sun4/OBJ/zs_bsctables.o \ /usr/sunlink/bscrje/sys/sun4/OBJ/zs_bsctables.o 4. Remake the kernel: # cd /usr/sunlink/bscrje # install.bscrje Reboot with the new kernel. ---------------------- Documentation Changes: ---------------------- None.