SyncSwitch Mapping

SyncSwitch devices are deployed in pairs or groups. The data received at one SyncSwitch's serial port is sent over an IP connection to a remote SyncSwitch and transmitted out its serial port. Data also flows in the opposite direction between the same two SyncSwitches.

At what level this switching is performed depends on the protocol selected for the serial port.

When the serial protocol is raw framed synchronous, data is switched by HDLC frame. That is, frames with a starting and ending flag (hex 7E) are received, placed in an IP datagram, forwarded over the IP network to a remote SyncSwitch, and then sent out a serial port on that remote SyncSwitch. No interpretation of the contents of the frame are preformed other than checking the CRC bytes. A mapping table is built indicating a one-to-one mapping (replacing a leased line) or one-to-many mapping (replacing a multidrop line) between a local serial port on a SyncSwitch and serial port(s) on a remote (IP-connected) SyncSwitch(es).

When the serial protocol is raw unframed synchronous, no framing of data (no flag) is required for the data received on the serial ports. The data is simply received bit-by-bit, placed in an IP datagram, forwarded over the IP network to a remote SyncSwitch where the bits are replicated out a serial port. Using the link configuration, you can control how many bytes of received data are placed into the IP datagram before it is forwarded to the remote SyncSwitch. A mapping table is built indicating a one-to-one mapping between a local serial port on a SyncSwitch and a serial port on a remote (IP-connected) SyncSwitch.

When the serial protocol is X.25, an X.25 connection is maintained by each SyncSwitch and the device attached to its serial port. The SyncSwitch acts as a layer 3 (packet level) switch. That is, when an X.25 call request is received by the SyncSwitch, it looks at the called address and forwards the call on to a remote SyncSwitch which then sends the call request out its serial port. All packets which follow on the virtual circuit that this call request establishes will be switched between these two serial ports. The administrator builds a mapping table which associates X.25 called addresses with local and remote serial ports. Multiple virtual circuits may be setup at the same time. These virtual circuits need not be between the same two SyncSwitches.

Information on status and finding problems with SyncSwitch mapping can be found in a section of the Administrator's Guide.

Port Mapping for Raw Synchronous Ports (Framed or Unframed)

With raw synchronous ports, SyncSwitch devices are deployed in pairs or groups. A mapping table is configured to associate a serial port on one SyncSwitch with serial port(s) on a remote SyncSwitch(es) across the IP network.

One SyncSwitch acts as the Master device and the others as Slaves. A mapping table is configured only in the Master SyncSwitch. The Master uses the table to build the associations while the Slaves simply wait for the Master to do the work. There are no requirements related to the order in which the Master and Slave SyncSwitches are started. If the Master SyncSwitch is running before any Slave is available, it will periodically retry to build the associations. If any of the SyncSwitch are rebooted, the association will be made again as that SyncSwitch is running again.

In most cases, SyncSwitches will be installed in pairs. Everything received on the Master SyncSwitch's serial port will be sent out the Slave's and vice versa. However, a multidrop environment can also be replicated using a set of SyncSwitches. Everything that is received on the Master's serial port is sent out all of the Slave SyncServers' serial ports. Anything received on each Slave's serial port will be sent out the Master's serial port.

Setup Switch Mapping

The SyncSwitch Mapping window is obtained by selecting Switch Mapping from the left-hand navigation. Any mappings already configured will be shown at the top of the page.

To add new mappings:

Type in the local link number involved in the switching.
Type in the IP address of the Slave (target) SyncSwitch
Type in the link number to be used on the Slave (target) SyncSwitch
Click Add to add the mapping.
If you are using a multidrop setup as described above, repeat for the other Slave SyncSwitch links

Again, this should only be configured into one of the SyncSwitches in the connection group.

Edit SyncSwitch Mapping

To delete a local-to-remote link mapping, select the check box of the Target Host to be deleted and click Apply.
To edit a mapping, make all required changes to the Local Link #, Target Host address or Target Link # and click Apply.

Port Mapping for X.25 Ports

With X.25 ports, the SyncSwitch can perform packet switching on switched virtual circuits (SVCs) or permanent virtual circuits (PVCs). SVC switching is based on the called X.25 address and begins when a call request arrives at the serial port. PVCs switching begins as soon as the SyncSwitches involved are running.

Define Packet Switch Mappings

For SVCs, on the SyncSwitch which will receive the call at its serial port:

Select X.25 Packet Switch Mapping from the left-hand navigation.
In the Add X.25 SVC Mapping table add the called X.25 address, IP address of a target host (remote SyncSwitch) and the target netid (which serial port should be used on the remote SyncSwitch). This will be used to direct calls received on the local serial port to remote SyncSwitches.
If you wish to redirect the call to another serial port on the same SyncSwitch, enter local in place of an IP address.
You can also enter default in place of a numeric X.25 address. All calls with a called X.25 address not matching other entries in the table will be directed to the specified target.
Click Add. The new mapping will be added to the SyncSwitch X.25 SVC Packet Switch Mapping table.
Repeat this procedure for every different X.25 address required.

For PVCs, on one of the SyncSwitches involved:

In the Add X.25 PVC Mapping table add the local netid (serial port number), local logical channel index (LCI), IP address of a target host (remote SyncSwitch), the target netid and LCI and the packet and window size used on the PVCs. This will be used to switch packets received on one of the indicated serial ports to the other serial port.
If you wish to switch packets between two PVCs on the same SyncSwitch, enter local in place of an IP address.
Click Add. The new mapping will be added to the SyncSwitch X.25 PVC Packet Switch Mapping table.
Repeat this procedure for every different PVC pair required.

Edit Mappings

To delete a Packet Switch Mapping, select the check box of the entry to be deleted and click Apply.
To edit a Packet Switch Mapping, make all required changes to the fields and click Apply.