R2511-HP MSR Router Series Terminal Access Configuration Guide(V5)

11
UDP RTC one-to-one transparent transmission
This mode is mainly applied to voice transmission. TCP RTC transparent transmission has a certain
forwarding delay, and is not suitable for voice communications. Because the voice service does not
require high reliability, voice data can be transmitted through UDP. This mode provides one-to-one
transmission in synchronous mode, but does not support asynchronous mode.
Filtering of flow control characters
Access devices send flow control character strings received from terminals to the FEP. If the FEP receives
a packet that contains both the flow control characters 0x13 to enable flow control, and 0x11 to disable
flow control, the FEP enables flow control but does not disable it. As a result, the FEP stops sending data
to the corresponding terminal, and the display pauses until you disable flow control by pressing the
shortcut key. To prevent this issue, configure the device to filter flow control characters out of the data
received from terminals and to perform flow control by itself.
TCP_NODELAY
In TCP RTC many-to-one or TCP one-to-one transparent transmission mode, the RTC server complies with
RFC 896 to use the Nagle algorithm to prevent network congestions caused by a large number of TCP
packets. However, this algorithm also causes time delay during TCP packet transmission for application
programs, especially for interactive ones. The RTC server allows you to disable the Nagle algorithm by
setting the TCP_NODELAY option.
Terminal access specifications
Terminal access initiator specifications
Number Item Descri
p
tion
1 Maximum number of TTYs
255. This number is subject to the number of router
interfaces available for terminal access. For TTY
terminal access, this number is also subject to the
number of FEPs that can be configured.
2 Maximum number of APPs 2040.
3
Maximum number of VTYs
supported by each TTY
8.
4
Types of interfaces supported by
terminal access
Asynchronous serial interface on interface modules
such as 8AS, 16AS, 8ASE, and 16ASE.
5 Terminal emulation type VT100 and VT200.
6 Terminal baud rate Ranges from 300 bps to 115200 bps.
7
Access types supporting
asynchronous terminals
TTY, Telnet, ETelnet, SSH, TCP_11_Client,
TCP_11_Server, TCP_N1_Server.
8
Access types supporting
synchronous terminals
UDP_11_Client, UDP_11_Server, UDP_1N_Server,
TCP_N1_Server.
Terminal access receiving router specifications