TCP to X.25 general purpose Gateway Appliances for the transfer and routing of data between X.25 and TCP/IP networks
The highly versatile and resilient FarLinX TCP-X25 GP Gateway appliance range handle general purpose routing and data translation between TCP and X.25 networks |
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| The FarLinX TCP-X25 GP Gateway datasheet may be downloaded here, (PDF format). If you require an Acrobat Reader to view the datasheet just click on the 'Get Acrobat Reader' button to obtain a copy. |   |
Overview
The FarLinX TCP-X25 GP Gateway provides a very reliable solution for inter-connection of applications between TCP/IP and X.25 networks.
Key Features
- General Purpose TCP to X.25 data translation with a very wide variety of modes including: fixed routes, dynamic routing, RFC1006, Cisco RBP compatibility, header stripping and parity correction
- High performance, non stop operation - up to 1000 messages per second
- 3 Models, equipped with 1, 2 or 4 X.25 lines, and up to 4000 SVC and PVC connections
- Switching of X.25 connections between X.25 lines and routing over TCP
- Multiple Gateways providing Resilience with Load Balancing
- Simple configuration with a Web accessible Configuration Application
The Gateway operates as a general purpose means for connecting a variety of different TCP/IP equipment to X.25 services. Similarly, the Gateway can also inter-connect existing legacy terminals attached to an X.25 network to Host systems with TCP/IP interfaces. An X.25 switch function is also included in the 2 and 4 line models.
The product can support protocols when the X.25 Host system treats the incoming X.25 data as a character stream. It can also convert the data when a header is used to describe the message payload within the TCP connections and remove this header on the X.25 virtual circuits. Data types supported include: RFC1006, Cisco RBP and special character delimiting. Dynamic routing is supported where the Client TCP application determines the X.25 address and call parameters used at the time the connection is established. The Gateway can provide connectivity to several different Host systems at the same time with each can have different data conversion configurations.
The Gateway also support X.25 Data Switching over TCP this allows X.25 devices to be interconnected via an IP network without the layer 3 overheads associated with XOT.
Up to 2048 transactions can be handled simultaneously over each X.25 line. There are 3 versions of the Gateway providing scalable solutions, starting with the entry level GP Gateway-1 version supporting up to 254 simultaneous connections with 1 X.25 line to the GP Gateway-4 version allowing up to 4,000 connections over 4 X.25 lines.
Two or more Gateways can be used in a load balanced, resilient configuration that has no single point of failure.
This Gateway can be used in conjunction with ISODE's X.400 Server's to provide X.400 messaging over X.25.
Typical Applications
- Conversion of legacy X.25 connections and data to TCP connections
- X.25 to TCP/IP resilient Hub
- 4 port X.25 switch with selective routing of data over TCP/IP
- Reproduction of X.25 connections mapped over an IP network
- Provides an X.25 Gateway to inteface with X.400 Servers.
GP Gateway Operation
Example network configuration using the FarLinX TCP-X25 GP Gateway to interlink the TCP/IP and X.25 networks |
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The Gateway provides connection establishment and data packetization services for general protocols to allow applications sending data over TCP/IP to interface to X.25 connected hosts. The Gateway provides routing facilities to select the appropriate Host from those available and maintains X.25 sessions to the Host as required.
The Gateway listens on a number of TCP ports – one port per configured X.25 Host. When a client establishes a TCP connection to the Gateway, the Gateway sets up an X.25 virtual circuit to the appropriate Host. Once the end-to-end connection is complete, the messages can be transferred.
At the end of the transaction, if the terminal disconnects, the Gateway will clear the X.25 virtual circuit. Alternatively, if the Host clears the X.25 virtual circuit first, the Gateway will disconnect the TCP connection to the terminal.
An X.25 Switch function provided on some models of the Gateway can switch X.25 calls between X.25 connections and permit selective filtering of calls to TCP.
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TCP to X.25 data translation functions
The Gateway supports a wide range of TCP to X.25 data translation and connection functions, these include:
- Character stream
- ETX terminated messages
- Special character terminated messages (customisable)
- Message header conversion - types available 2 or 4 byte ASCII or Binary length representation
- Custom message header conversion
- RFC1006 - ISO Transport Class 0 protocol data units, using the RFC-1006 encapsulation on the TCP connection
- Cisco RBP - Record Boundary Preservation
- X.25 Parity conversion - the Gateway performs any required parity adjustments and removal on the x.25 connection
Many of the functions can be configured for the same connection for maximum flexibility.
Connection Routing and Address Mapping
The FarLinX TCP-X25 GP Gateway can support routes to 2,000 different X.25 hosts. Similarly, when using the called X.25 address as the routing key, incoming X.25 calls can be routed to thousands of different TCP/IP hosts.
When making connections to the X.25 network, the Gateway has the capability of mapping the source IP address to a calling X.25 address, thus allowing the destination X.25 host to identify the connection source uniquely.
The Dynamic routing option allows the X.25 address (NUA) and call parameters to be set by the remote application at the time each X.25 connection is established. X.25 packetisation information is passed to the application.
The main modes supported include:
- Statically defined routing
- DRPD - the Dynamic Routing Packetized Data format allows TCP connected applications to dynamically setup the X.25 connection
- X.25 Data Switching - allows X.25 devices to be interconnected via an IP network without the overheads associated with XOT
- PAD Routing - PAD or Dynamic routing may be employed to allow the TCP client application to specify the X.25 call parameters
Performance
and Expandability
The FarLinX TCP-X25 GP Gateway easily handles very high transaction loads. Support for large numbers of X.25 lines and multiple Gateways provides enormous scalable expansion capability and resiliency. The main performance and expansion features of the Gateway are:
- Up to 1000 messages per second on each Gateway
- Up to 4000 simultaneous connections
- Multiple load balancing Gateways with up to 32 sharing a single IP address
- X.25 line speeds up to 8 Mbits/s
- 3 models - 1, 2 and 4 X.25 port versions
- X.25 Networks, Leased Lines and X.25 Dialup connections supported
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Overview
of Resilient Operation
The FarLinX TCP-X25 GP Gateway can be deployed in a wide variety of ways to achieve the level of resilience required by the application. The level will depend on the value of the data traffic and the acceptable degree of user intervention required to rectify any problem. The aim with resilience is to remove single points of failure. Resilient configurations using more than one Gateway also allow improved performance by sharing the traffic load between several machines.
Network Line Redundancy
To achieve network line redundancy, a single FarLinX TCP-X25 GP Gateway may operate with two or more X.25 lines. It can route data over any active line connected to the Gateway so that if one line goes out of operation then the other lines continue to be used automatically.
Gateway Redundancy and Load Balancing
For fully resilient operation, two (or more) FarLinX TCP-X25 GP Gateways may be deployed. They can be either configured for simple failover from a primary to a backup machine or for full load balanced operation. In Network Load Balancing (NLB) mode both failover and load balancing of the connections are provided thus ensuring there is no single point of failure and that there is no performance bottleneck.
The built in Gateway Supervisor checks the state of the X.25 network lines and as these change state between fully operational and faulty it automatically enables/disables the unit from the pool of FarLinX TCP-X25 GP Gateway's, thus managing the availability of that particular Gateway machine. Key events such as the loss of an X.25 line are recorded on a daily rotating event log.
Maintenance
Contract
FarSite recognises that this product is frequently used as a key component in networked systems and as such a guaranteed response to unexpected problems is required. A maintenance contract is available for the FarLinX TCP-X25 GP Gateway for priority service and rapid problem resolution.
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Technical
Specifications |
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| Product Name | FarLinX TCP-X25 GP Gateway-1 | FarLinX TCP-X25 GP Gateway-2 | FarLinX TCP-X25 GP Gateway-4 |
| Product code | FL2400 | FL2402 | FL2404 |
| Maximum simultaneous connections | 254 | 2048 | 4,000 (a maximum of 2048 per X.25 line) |
| X.25 Line count | 1 line | 2 lines | 4 lines |
| X.25 Switch module included | No | Yes | Yes |
Gateway Features |
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| TCP to X.25 Data translation modes | Character stream, ETX terminated messages, CR terminated messages, Message header conversion (types available Conv Hdr 2-bin, Conv Hdr 2-ascii, Conv Hdr 4-bin, Conv Hdr 4-ascii), Customisable message header conversion RFC1006, Cisco RBP, X.25 Parity conversion |
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| TCP to X.25 call routing modes | Statically defined routing, DRPD, X.25 Data Switching, PAD Routing |
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Data packets per second |
Up to 1000 packets of data per second | ||
| Resilience and load balancing | Yes, from 2 to 32 Gateways |
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| Logging key events | Events such as the connections being established and dropped, X.25 call fails, X.25 line down, and X.25 lineup are logged on a daily rotating log file | ||
Network connectors |
Connection cables are available with RS232C
(V.24), X.21, V.35 and RS530 connectors. The cables are ordered separately, see the Cable Table. |
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| Types of X.25 connection | X.25 network, leased line, X.25 dialup | ||
| X.25 feature summary | Speeds up to 8 Mbits/s |
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| LAN | 3 10/100 BaseT LAN ports, RJ45. Each port is for connection to a separate Network | ||
| Approvals | CE, FCC part 15 class A, UL | ||
| Power Requirements | Input voltage range: 100v to 240v Typical 60w (0.25amps at 230v), Peak 120w (0.5amps at 230v) |
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| Physical | Dimensions: metric: 429(W) x 282(D)
x 44(H) mm, imperial: 16.89”(W) x 11.1”(D) x 1.73"(H)
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| RoHS Compliance | Yes | ||
Product Name |
Description |
Product Code |
| UCR1 | Single RS232C (V.24, X.21bis) cable with male 25 pin D type (DB25) connector, 1.5 metres | FS6061 |
| UCX1 | Single X.21 (V.11, RS422) cable with male 15 pin D type (DB15) connector, 1.5 metres | FS6062 |
| UCV1 | Single V.35 cable with standard MRAC-34 (brick) male connector, 1.5 metres | FS6063 |
| UX35C | Single V.35 DCE cable with standard MRAC-34 (brick) female connector, suitable for internal clock generation only. 1.5 metres | FS6095 |
| U530 | Single RS530 cable with male 25 pin D type (DB25) connector, 1.5 metres | FS6064 |
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Information in this document is subject to change without notice.
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Last updated:
03-Apr-2008