Cabletron Systems SmartSwitch 6000 User Manual page 149

No Data Poll Period
No Resp Poll Period
Maximum Retransmissions
Outstanding Frames
Generate Clock
Rcv Clock (TT) from DTE
SNA Type:
Configuring SNA
If an RS-232 DCE port is directly connected to the DTE via the standard
Cabletron cable, the maximum supported speed is 64K. If longer cabling is
used, the maximum speed is 19.2K. (The EIA standard for RS-232
addresses speeds up to 19.2 Kbps.)
is the time between polls by this TPAD port of its PU (physical unit) when the PU has
no data to send. This parameter has no relevance on an HPAD port.
is the time between polls by this TPAD port of its PU when the PU is not responding.
The TPAD will continue to poll at this interval up to the number of times specified by
Maximum Retransmissions
is the maximum number of times the port will attempt to send a frame if the PU is not
responding. A larger value increases the probability of an eventual correct transfer
between DTE and DCE, but a smaller value permits faster detection of a permanent
error condition.
also called level 2 window size, is the maximum number of sequentially numbered
frames that can be waiting for acknowledgment. If this number is exceeded, no more
frames will be transmitted until an acknowledgment is received. A larger value allows
faster throughput.
Note that this parameter can be changed without disabling the link, except if the
existing value is within the range
modulus 8 or 128; anything greater is only modulus 128. Changing the modulus will
disable the link.)
specifies whether the port will generate the clock necessary to synchronize traffic over
the link. If the port is a physical DCE (determined by the port's I/O cable interface),
configure
Generate Clock
DTE, configure
Generate Clock
allows the clock to be looped back from the DTE using the TT (Terminal Timing)
signal, which can be helpful on high-speed lines. Generally, if the local interface is
physical DCE and the line speed is above 256 Kbps, this parameter should be set to
(Make sure the remote DTE is configured to provide the terminal timing.)
= XPAD, = TPAD,
0 1
the value to the next one in the list.
The most common SNA networking requirement is for communication between an
SNA host computer (PU type 4) and control units (PU type 2). This is accomplished
via an HPAD (Host PAD) and TPAD (Terminal PAD). The host computer FEP is con-
nected to the HPAD and the cluster controller is connected to a TPAD.
The XPAD is particularly useful for networking of statistical multiplexers and other
bit-sync devices.
. This parameter has no relevance on an HPAD port.
and the new value is greater than 7. (
0–7
as , since the physical DCE generates clock. If the port is
Y
as .
N
= HPAD, = NPAD. Pressing
2 3
0–7
at the Port screen changes
[L]
is
.
Y
8-7