Hello Ocporbust,

this serial interface is configured for a form of tunneling called STUN

every SDLC frame that is received is placed inside a TCP segment and sent to 10.0.14.1.

It should be related to some form of IBM or mainframe networking.

STUN SDLC is most commonly used in two environments: FEP to remote controller, and AS/400 to remote controller.

see

http://www.cisco.com/en/US/tech/tk827/tk369/technologies_tech_note09186a00800b451e.shtml#stun_sdlc

Hope to help

Giuseppe