CISCO-ALPS-MIB
The MIB module for Airline Protocol Support. ************************************************************** * Acronym Definitions * * * * ALPS : AirLine Protocol Support * * AX.25 : Airline X.25 * * EMTOX : Exchange of Mixed Traffic over X.25 * * ASCU : Agent Set Control Unit * * * ************************************************************** Overview of ALPS (AirLine Protocol Support) MIB ============================================== MIB description Document to refer: 'Configuring ALPS' section in Cisco IOS Command Reference & Configuration Guide. The ALPS MIB provides configuration and operational information for Cisco's Airline protocol support for IBM-P1024B(ALC) and Unisys-P1024C(UTS) protocols encapsulation over TCP/IP. The following entities are managed: 1. Peers 2. ALPS Circuits 3. ASCUs (Agent Set Control Units) 4. ALC interface 5. ALPS Host link interface to the host HOST(Emtox/Ax.25) <----> Central <---> IP Network <---> Remote <----> ASCU router router The router connected to the Host is called the Central router and the router connected to the ASCU is called the Remote router. We anticipate one Central router connecting to a large number of Remote routers. Each router has a local peer, which connects to its counterpart on the other router (referred to as the remote peer) via a TCP connection. ALPS circuits are set up over this TCP connection either on a permanent or on-demand basis. A logical grouping of ASCUs are connected via a single circuit - this has no connection to the physical interfaces that the ASCUs are connected to. The only restriction is that all the ASCUs should be directly connected to the same router. Multiple ASCUs can connect to a single serial interface and several terminals connect to an ASCU. However, terminals are not visible to the ALPS feature - the router talks only to the ASCUs. An ASCU can be identified by * the interface it is on and its Interface Address (IA) or * the circuit it is on, and its A1 and A2 values, which identify it within the circuit. Thus there are two ways of identifying an ASCU - <interface,IA> or <circuit-name,A1,A2> Circuit names are globally unique. The connection to the host is via one of two flavors of X.25 - either AX.25 (for PVCs) or EMTOX (for SVCs). Each X.25 VC corresponds to one ALPS circuit. There are several hostlinks between a host and the Central router and load balancing is done across these. EMTOX allows the host to dial out to a terminal. This requires the use of an X.121 to IP address translation table to connect to the appropriate remote peer.