Access 4000 X.25-TCP/IP Gateway

Software Features

• Dual serial ports individually configurable for X.25, async/serial, or HDLC/LAPB
• Serial ports support speeds up to 10Mbps
• Up to 1024 SVC and/or PVC logical channel connections on the X.25 interface
• Encapsulation method configurable on a per connection basis
• No re-configuration of X.25 devices necessary
• Easy to use web configuration GUI compatible with any Internet browser (HTTP and/or HTTPS)

Software

• Gateway connectivity between X.25 and TCP/IP devices or networks
• XOT (RFC 1613 - X.25 Over TCP)
• X.25 SVC and PVC – 1024 channels / link
• Comprehensive address matching and routing table
• Serial support for terminal server applications
• Telnet and SSH remote management logins
• Optional serial Console port management login
• SNMP polls and link alarms
• User-friendly web interface for easy configuration and monitoring

Hardware

• Dual (2) – RS232/V.24, V.35, X.21, RS530, RS449/V.36 ports
• Synchronous speeds 1200bps to 10Mbps, internal or external clock
• Asynchronous speeds 300 to 115200bps
• 10/100-BaseT Ethernet port
• USB host port for Flash Drive or serial adapter (1,2,4, or 8 port)
• 12VDC 1.3A powered from AC adapter
• -48VDC powered version optionally available
• Dimensions: 5.5” x 7.25” x 1.625” (D x W x H)
• Weight: 1.4 lbs
• CE and RoHS

Chassis Enclosure – Rear View

19" 1U Rack-mount Shelf

• PN: M4002-00-RM, 19" 1U Rack-mount shelf holds 1 or 2 Access 4000 units.



Custom Enhancements

Please contact Microtronix sales with your custom design requirements.

X.25 to TCP Conversion

The X.25 to TCP Conversion Gateway interfaces or bridges between X.25 and TCP/IP devices by interconnecting X.25 logical channels to TCP sockets using one of several encapsulation methods. The Gateway connects directly to X.25 DTE devices or to X.25 packet networks (DCE).

An important function of gateway conversion is the preservation of application messages. X.25 implementations delineate messages using packet sequences and a “More-bit” to reconstruct long messages. TCP, on the other hand, delivers messages as a non-delimited byte stream, and so requires the addition of an encapsulation header on top of TCP to preserve the boundaries of the message. Supported encapsulation methods include:

• XOT (RFC1613 - X.25 over TCP)
• RFC1006 Encapsulation (ISO Transport Service on TCP)
• Cisco RBP
• Odette FTP Encapsulation on TCP (as per RFC5024)
• 2-byte length header
• X.25 M-bit and Q-bit preservation header
• LINE mode for terminal applications
• RAW (when no encapsulation header is required)
• Custom encapsulation methods are available by request

In addition, applications sometimes send control information in X.25 packets with a Qualifier flag (Q-bit). This requires that the Q-bit is also preserved and indicated in the TCP message. Supported encapsulation methods are:

• Custom RFC1006 Encapsulation with Q-bit flag
• Cisco QRBP (Record Boundary Preservation with Q-bit flag)
• AEPN (Applied Innovation Encapsulation Protocol includes Q-bit support)

X.25 over TCP Encapsulation (XOT)

An XOT Gateway is typically used when the X.25 network or point-to-point connection between X.25 devices is being replaced with an IP network. By tunneling the X.25 packets over TCP, transparency is maintained while providing X.25 to IP address mapping and end-to-end X.25 logical channel number translation. X.25 devices do not need to be re-configured.

XOT to TCP Conversion

When an IP host supports X.25 on top of TCP (XOT) and relies on an external X.25 gateway to convert back to X.25, a second X.25-TCP gateway would be required for conversion to a TCP/IP device. The Access 1000 Gateway goes one step further by combining XOT–X.25 de-encapsulation and X.25-TCP conversion internally, eliminating the X.25 physical interface and associated overhead or bottleneck.