OSI/TS Configuration and Management Manual
Configuring the OSI/TS Subsystem
OSI/TS Configuration and Management Manual—424831-001
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Configuring TSP Processes
ESISESCONFTIME Attribute
The ESISESCONFTIME timer defines how often a system reports its availability to an 
intermediate system on the same subnetwork.  The lower the value, the more quickly 
other systems on the subnetwork become aware of the reporting systems availability. 
You must consider the tradeoff between this increased responsiveness and the increased 
use of resources in the subnetwork and in the recipient system.
If your subnetwork includes an intermediate system, there is no need to change the 
default value. If you do not have an intermediate system, and you anticipate that the 
NSAP-SNPA mapping will change infrequently, you should set this attribute very high. 
The value must be set small enough to detect changes in the NSAP-SNPA mapping in a 
timely manner, yet large enough to prevent unnecessary messages being sent.
ESISQUERYRETRY Attribute
The ESISQUERYRETRY attribute defines the number of times the ES-IS routing 
exchange protocol tries to obtain an NSAP-SNPA connection before giving up. The 
value must be set low enough to warn you of problems with congestion, yet high enough 
to allow for the occasional retries that are normal in every network. The default value is 
usually sufficient.
ESISQUERYTIME Attribute
The ESISQUERYTIME attribute defines the amount of time the ES-IS routing exchange 
protocol waits for a reply to a request for an NSAP-SNPA connection before retrying or 
giving up. In high-traffic networks, this value should be set fairly high. It is generally 
better to allow a longer time interval than to incur many retries, which increases the 
chance of failure and increases system overhead.
IPLIFETIME Attribute
The IPLIFETIME attribute defines the amount of time that an IP data unit (IPPDU) can 
live during its transit through the subnetwork(s) before being discarded . You should set 
this value high enough to ensure that an IPPDU can get to its destination before its 
lifetime expires, yet low enough to ensure that resources are not allocated unnecessarily. 
If you are using SNDCF, you should set this value higher to account for longer transit 
time.
Configuring TSP Processes
Each TSP process can support 512 transport connections.  The actual limit in your 
subsystem may be fewer than 512, depending on its specific configuration parameters 
(for instance, TPDU size or message size). You can assign multiple TSP processes to 
one physical X.25 line.  Although you can assign multiple TSP processes to a single 
TLAM/PAM I/O device, the configuration would not conform to OSI standards and is 
therefore not recommended. See Section 5, OSI Transport Services
 for more 
information on multiplexing.










