Cisco 11.0 BT Release Notes page 38

show extended channel tn3270-server
Table 5
Field
LINK type
DESTINATION mac-address or
PU-name
R-LSAP number number
38 TN3270 Server Commands
Show tn3270-server Field Descriptions (Continued)
Description
LINK type is either internal adapter type and internal adapter
number or dlur if it is a SNA Session Switch PU.
If a direct PU, then it is the destination MAC address, otherwise, it
is the name of the partner PU.
Remote and local SAP values.