RAD APD-2HS Miniature FRAD/X.25 PAD  

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APD-2  2-channel async Packet Assembler/Disassembler (PAD/FRAD)

RAD APD-2HS Miniature FRAD/X.25 PAD  


  • 2-channel async Packet Assembler/Disassembler (PAD/FRAD)
  • One synchronous Frame Relay or X.25 link
  • X.32 for dial-up modem
  • SNMP management via RADview application on a PC station
  • Synchronous link data rate:
    APD-2: up to 64 kbps
    APD-2HS: up to 256 kbps
  • Async channels data rate: up to 115.2 kbps
  • Synchronous link interfaces:
    APD-2: V.24/RS-232
    APD-2HS: V.24/RS-232, V.35



  • Both channels are configured and monitored by the built-in management agent. The async channels can act according to X.3, X.28, and X.29 profiles. Async traffic can be packetized directly over the Frame Relay network, or packetized over the X.25 protocol and encapsulated over a Frame Relay network.
  • The asynchronous channels operate at data rates from 75 bps up to 115.2 kbps.
  • Hardware flow control.


  • APD-2/2HS provides access to public or private Frame Relay networks. Async traffic is sent over the Frame Relay network, either directly over Frame Relay, or async to X.25 over Frame Relay (reliable async transfer over Frame Relay, Annex G). See Figure 2.
  • A unique funneling method controls network congestion and moderates feeder throughput speed.
  • LMI and ANSI PVC management protocols are supported, and operation is in compliance with ANSI T1.606, T1.618, T1.617 Annex D and ITU Rec. Q.922, Annex A.


  • X.25-configured links support permanent virtual circuits (PVCs) or switched virtual circuits (SVCs). Link packet size is up to 4096 bytes.
  • APD-2/2HS supports both mandatory and additional ITU X.2 facilities.
  • Dial-up X.25 links are supported via a dial-up modem controlled by a DTR signal.


  • APD-2/2HS supports X.32 protocol, which enables users to access the X.25 network from an extended distance via a dial-up modem. The X.32 protocol supports V.25 bis commands.


  • An integrated management agent can be accessed from any point in the network through an X.25 address or can be managed locally via a control port.
  • The management agent enables configuration, compilation of statistics and status reports, and diagnostics. The management agent can be programmed to periodically send statistics and status reports for up to five address locations in the network, for updating purposes. An alarm event can also be transmitted.
  • APD-2/2HS contains an SNMP agent that allows access from any point in the X.25 / Frame Relay network via the IP address.
  • Configuration, monitoring and controlling of all network resources can be performed from a RADview-PC SNMP management station.
  • The SNMP agent supports private and standard MIBs, including MIB II with RFC 1213, RFC 1381 and RFC 1382 for X.25, and RFC 1315 for Frame Relay.


2-port miniature PAD/FRAD

2-port miniature high speed PAD/FRAD

* Specify external power supply:
115 for 100-115 VAC operation
230 for 230 VAC operation
(default is without power supply)

External power supplies can be ordered separately:

for stand-alone regulated 230 VAC to 5 VDC / 700 mA power supply

for stand-alone regulated 115 VAC to 5 VDC / 700 mA power supply


Figure 1. Basic PAD / FRAD Application

Figure 2. Async to X.25 Application

Figure 3. Direct Async to Frame Relay Encapsulation

Figure 4. Reliable Async over Frame Relay




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