IST2384E

Explanation
This unsolicited message is issued when a write
buffer is discarded as the result of congestion on the outbound data
staging queue. A write buffer can contain up to 64 KB of TCP/IP packets.
Write buffers are discarded to protect against the overuse of system
resources, specifically ECSA storage. This message might mean that
a TCP/IP stack contention or dispatching problem exists.
This
message remains on the screen until congestion is alleviated or until
the message is manually deleted. 
In the message text:jobname
The 1 – 8 character TCP/IP job name that is used to start
the TCP/IP address space.
trlename
The name of the TRLE that is experiencing congestion.

System action
If congestion subsides for at least 30 seconds,
this message is automatically deleted. If congestion persists, message
IST2384E is deleted and reissued every 5 minutes.

Operator response
You can use the DISPLAY NET,TRL and DISPLAY
NET,TRL,TRLE=trlename commands to determine
which interfaces or devices are experiencing congestion. Message IST2386I
provides the number of write buffers that are discarded. These interfaces
or devices can be stopped or recycled in an attempt to eliminate the
congestion.

System programmer response
If the condition is persistent, take
the following actions:Study and possibly adjust the TCP/IP dispatching priority.
If the condition continues to persist, take the following actions:If you have access to IBMLink, search for known problems in this
area. If no applicable matches are found, take a dump of the TCP/IP
address space and the VTAM® address
space, and report the problem to IBM® by
using the Electronic Technical Report (ETR) option on IBMLink.
If you do not have access to IBMLink, take a dump of the TCP/IP
address space and the VTAM address
space, and report the problem to the IBM software
support center.

User response
Not applicable.

Problem determination
Not applicable.

Source
z/OS® Communications
Server SNA

Module
Use the modifiable VTAM start
option MSGMOD=yes (f  procname,vtamopts,msgmod=yes
or f procname,msgmod=yes) to display the issuing
module when a message is issued. See z/OS Communications Server: SNA Operation and z/OS Communications Server: SNA Resource Definition
Reference for more information about start options.

Routing code
2

Descriptor code
11

Automation
Automation is recommended because persistent discarding
of outbound data can have a significant impact on latency and throughput.

Example
 IST2384E PACKETS DISCARDED FOR TCPCS - NSQDIO11 IS CONGESTED