ESL Settings for Control & Security

Ether-Serial Link Security

As network devices, Ether-Serial Links need to be secure from inadvertent changes, disruptions, and malicious interference. To that end, LAVA Ether-Serial Links have a password-protected administration allowing Links on a network to be secured against unauthorized network configuration. Essential device settings, such as device name, IP address, network submask, and gateway address, cannot be changed without authorized access. At the same time, users who need to access and configure individual ports on a link can do so, with the administrator’s permission. The Ether Link administrator can allow a user to modify their port’s operating mode and parameters as needed. In the event that multiple users are accessing the same port, the administrator can also lock the port against being reconfigured or reset, thus preventing one user from overriding or locking out another user.

The administrator can set access to the ports of an Ether-Serial Link to restrict use to a trusted set of IP addresses, configurable in a wide number of ways. Ports can be disabled, enabled, and reconfigured on a port-by-port basis without disrupting activity on the link as a whole.

Port Modes

Ether-Serial Links have multiple modes of operation. As well as operating as basic remote serial ports, Ether-Serial Links have a number of other port modes that permit them to be used in numerous versatile, powerful, and cost-reducing ways. Users who want to communicate with an Ether-Serial Link across gateways or routers can easily configure a port on an Ether-Serial Link to operate in RFC 2217 mode. This allows serial port configuration commands and serial data to be sent to an Ether-Serial Link using the RFC 2217 framework for serial port control over Telnet. For those not familiar with RFC 2217 (the Telnet COM Port Control Option), the text of the actual RFC (Request For Comments) is available at or at any number of other sites.

An Ether-Serial Link can also act as a raw client or raw server. These are non-driver modes, allowing connections to be established regardless of operating system. In these modes the Ether-Serial Link acts as either a client, initiating communication with a pre-assigned server, or as a server, presenting its data to a client request.

Modem mode lets two Ether-Serial Links effectively operate as a modem connection across a network, a WAN, or the Internet. This “modem eliminator” mode can provide great savings by avoiding the high costs of long distance or leased phone lines.

  1. A pair of Ether-Serial Links can also operate as a long serial cable when in cable extender mode. In this mode, the Links are connected to the PC by their serial ports and the Ethernet side of the Links forms the “cable”?
  2. RAS server mode provides an interface to shared network based interconnections (Remote Access Services).
  3. The variety of modes available to Ether-Serial Link users now enables these devices to fill almost any serial-to-network adapter need.
  4. Bound to Connect: Robust Ether-Serial Link connectivity.

One of the strongest features of LAVA Ether-Serial Links is virtually invisible, most of the time. The driver for LAVA Ether-Serial Links lets PCs “bind” to the ports on the Ether-Serial Link in a number of ways. Port binding establishes a particularly robust connection between a PC and the port on an Ether-Serial Link. The market for “serial port hubs,” “serial device servers,” “serial terminal servers,” “Ethernet-serial converters,” and other similar devices is crowded with “me-too” devices. It’s safe to say that most of these devices will work. But questions to ask prior to making a purchase include:

  • How well will they manage the connection between the serial device and the network?
  • How long will that connection hold?
  • What compromises are needed to create a solid and lasting connection?

LAVA’s solution answers these needs via virtual port binding.

Basically, port binding works like this. Data travelling between the COM port on an Ether-Serial Link and the PC communicating with that port needs a TCP/IP connection. This connection involves sending data to the IP address and desired port of the Ether-Serial Link. That’s fine, as long as the IP address is valid, and matches an actual Ether-Serial Link. But “what if the IP addresses of the network are not static (as when IP addresses are supplied by a DCHP server)” In such cases, the PC needs other methods to establish and maintain communications with its target, because a given device cannot be counted on to always have the same IP address.

Fortunately, other device identifiers exist on networks. One is the MAC (Media Access Control) address of a device. All network devices, regardless of type, size, or manufacturer, must have a MAC address, a number that is unique for every device. In addition, LAVA Ether-Serial Links also have user-definable device names. These identifiers, in conjunction with LAVA “Discovery Protocol,” enable all LAVA Ether Serial Link devices on a subnet to respond to a LAVA-specific broadcast issued by a PC (with the LAVA driver running). Think of this as a hail to all Ether Serial Links in the neighborhood – they will reply with their IP address, MAC address, and device name.

Once the PC has received answers to its hail, LAVA software can match up the information it receives with the information already known, according to binding “rules” that the user of an Ether-Serial Link can set up. These rules will enable a connection to be re-established if, for example, IP addresses on a network change, or one Ether-Serial Link is replaced with another intended to serve in the same capacity. The bottom line is LAVA Ether-Serial Links intelligently maintain their connections. Connect Simply.

LAVA Computer MFG headquartered in Toronto, ON, Canada, designs and manufactures serial parallel I/O boards and Ethernet-to-serial device servers widely used in Point of Sale, Kiosk, Gaming, Industrial Automation, Hospitality, Telecom, Security & Access Control industries. With well over a million LAVA products built into workstations, servers, and POS systems since 1984, LAVA I/O boards and Ether-Serial Links are trusted by resellers, distributors, OEM’s and system builders in over 47 countries worldwide. Designed for lifetime performance, each LAVA connectivity link is individually tested and covered by the LAVA Lifetime Warranty.