November 5, 2009

Perle Terminal Servers provide firewall-safe serial connections with HTTP Tunneling

Perle IOLAN Terminal Servers, with HTTP tunneling, provide secure internet connections between serial devices that are behind firewalls

NASHVILLE, TN—November 5, 2009— Perle Systems proudly presents the first and only Terminal Server on the market able to provide HTTP Tunneling. By incorporating HTTP Tunneling technology, Perle IOLAN’s are able to securely connect and transport serial data between remote serial peers over the internet without the need to change firewall settings.

Connecting to remote serial communication based devices, whether it is the serial console port on a piece of equipment or an industrial PLC, is a simple matter when using a closed, dedicated network. By using a serial to Ethernet terminal server such as a Perle IOLAN, serial data to and from the port are packetized onto Ethernet packets and transported to a remote IP application or a peer IOLAN where it is converted back to serial for connection to the remote serial device peer. The IP address of all the elements involved are known and the client server relationship is clear.

When attempting to do this across the internet however, it is not as simple. In corporate environments, connections to the internet are safeguarded by firewalls, routers and proxy servers. The individual device IP addresses appear as a dynamic translated network address (NAT) to entities on the internet and are not directly addressable.

Firewalls are also very particular on the type of IP sessions that are allowed to and from the internet. Hypertext Transfer Protocol (HTTP) the standard used by Internet browsers operating under TCP port 80, is firewall-safe and is universally allowed to pass through. Other protocols such as SSH (port 22) or Telnet (port 23) are normally blocked. To allow these, the firewall configuration must be changed which compromises the existing corporate security policy.

“Perle IOLAN’s with HTTP Tunneling technology solve this problem, says Al Davies, Director of Product Marketing for Perle Systems. “This is how it works. A remote HTTP Tunneling IOLAN client behind a firewall establishes an HTTP session with an IOLAN server counterpart on the internet located in an enterprise DMZ (De-Militarized Zone) or Service Provider location. By utilizing standard HTTP GET and SET commands, these peers now have the ability to exchange packets. Serial data from an attached device can now be converted by the IOLAN and sent across the internet to its HTTP tunnel peer. The IOLAN peer will then exchange the packet back to serial. The result is a firewall-safe, seamless serial connection through the internet.”

HTTP Tunneling is available in IOLAN Firmware Release Version 4.1

Find out more about Perle Terminal Servers

About Perle Systems
Perle Systems is a leading developer, manufacturer and vendor of high-reliability and richly featured serial to Ethernet networking products. These products are used to connect remote users reliably and securely to central servers for a wide variety of business applications. Product lines include Console Servers for Data Center Management, Terminal Servers, Device Servers, Ethernet I/O and Serial Cards. Perle distinguishes itself through extensive networking technology, depth of experience in major real-world network environments and long-term distribution and VAR channel relationships in major world markets. Perle has offices and representative offices in 11 countries in North America, Europe and Asia and sells its products through distribution and OEM/ODE channels worldwide.