Digi ConnectPort LTS 16, Справочник по командам, Страница: 113 / 169

Command descriptions set service
ConnectPort® LTS Command Reference 113
Configurable TCP keepalive parameters, for example, how many keepalives to send and when to send
them are configured globally via the “set network” command (see "set network").
nodelay={on|off}
Used to allow unacknowledged or smaller-than-maximum-segment-sized data to be sent for the
specified range of network services.
The “nodelay” option disables Nagle’s algorithm, which is on by default, for some TCP services. The
purpose of Nagle's algorithm is to reduce the number of small packets sent. The algorithm establishes
not sending outgoing data when there is either unacknowledged sent data, or there is less-than-
maximum segment size (typically around 1500 bytes for Ethernet) worth of data to be sent. While this
algorithm allows for efficient data transmission, there are times when it is desirable to disable it.
delayed_ack=0-1000
The time, in milliseconds, to delay sending ACK packets in response to received data for the specified
range of network services. The default is 200 milliseconds.
Setting this option to 0 (zero) sends an ACK packet back acknowledge the received data immediately.
Setting it to any other value means that the ACK packet will be sent after the specified time. If the
network services generate new data during that time, the ACK packet will be sent along with the data
packet.
You can use this setting to avoid congestion and reduce network traffic, However, do not change this
option from its default setting unless you have a solid understanding of network services and data
transmission, or have been instructed to make the change.
Supported network services and their default network port numbers
The following table shows the network services controlled by the “set services” command, the
services provided, and the default network port number for each service.
In products that have multiple serial ports, the network port number defaults for various services are
set based on the following formula:
base network port serial port number
For example, the Telnet Passthrough service is set to network port 2001 for serial port 1, 2002 for
serial port 2, 2003 for serial port 3, etc.
If you change a network port for a particular service, that is the only network port number that
changes. That change does not carry over to the other network ports. For example, if you change the
network port number Telnet Passthrough from 2001 to 3001, that does not mean that the other
network ports will change to 3002, 3003, etc.
There are two types of network services available:
n
Basic services, which are accessed by connecting to a particular well-known network port.
n
Passthrough services, in which a particular serial port is set up for a particular type of service.
To use the service, users must both use the correct protocol and specify the correct network port. The
serial port profile must also be set to a profile that allows passthrough, such as the Console
Management. For example, assuming default service ports and using a Linux host, here is how a user
would access the Telnet passthrough services:
#> telnet digi16 2101