Technical data

PortServer Terminal Server Page 113
PortServer Port Numbers
The PortServer provides two ranges of TCP/IP service numbers that you can connect to from
other systems:
2001 - 2099 Telnet Connect
2101 - 2199 Raw Connect
A connect made to any 20XX port uses the Telnet protocol, providing full Telnet compatibility.
You would use the 20XX ports in commands like:
pr myfile | telnet dbps-nodename 2001
A connect to any 21XX service is a raw connection, passing 8-bit clean data at all times. This is
useful with the RTTY command described on page 101, and for custom applications.
The last two digits in each number indicate to what port or group the user is to be connected. If
the last two digits are 01 - 16, a connection is made to the specified port. Numbers greater than
16 indicate a port group number, as configured with set port group=group_number (see
page 53).
When several PortServer ports are configured with the same group number, they work like a
telephone “hunt group.” Any attempted connection goes to the lowest numerical port number that
can currently accept a connection.
The altip command (page 41) can be used to define alternate IP addresses for telnetting to a
port or huntgroup. (This option does not support raw connect.) You could replace telnet abc
2080 with telnet abcalt, assuming that abcalt has an IP address associated with group
80 in the altip table, and abcalt is defined in a host table. The “group number” (rightmost
two digits) should be in the range 17-99.
Choosing the wrong range of service numbers, (for example, 20xx instead of
21xx) is a common source of user problems.