曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
are those recei,ved correc~lya nd in sequence following
the I-frame requested; the specific I-frame to be
retransmitted is indicated by the N{R) in the SREJ
comma.nd/response:
N(R)
N(R)
N(R)
N(R)
0 0 0
P I 0 0
c) the clearing of a busy condition shall be indicated by b) the SREJ exception condition is cleared (reset) upon
the Iransn-lission of an PCR, REJ, SABM, or UA with receipt of a11 I-frame with an N(S) cou~e~qtu al to the
or witl~out the PLF bit set to "1". N(X) of the SREJ;
7/11/96
No. 71
Part I Annex 10 - Aeronautical Telecommunications
c) after a station transmits a SREJ it is not permitted to
transmit SREJ or REJ for an additional sequence error
until the first SRET error condition has been cleated;
d) I-frames that have been permitted to be transmitted
following the I-frame indicated by thc SREJ are not
retransmitted as the result of receiving a SREJ; and
e) it is permissible for additional I-frames pending initial
transmission to be transmitted following the retransmission
of the specific I-frame requested by the SREJ.
8.6.4.2.7.3 The U-frame commands and responses shall
be used to extend the number of link conlrol functions.
Transmitted U-frames do no1 increment the sequence counls a1
either the transmitting or receiving station.
a) The U-frame mode-setting commands (SABM, and
DISC) shall be used to place the addressed station in
the appropriate response mode (ABM or ADM) where:
1) upon acceptance of the command, the station send
and receive state variables, V(S) and V(R), are set
to zero;
2) the addressed station confirms acceptance at the
earliest possible time by transmission of a single
unnumbered acknowledgement, UA;
3) previously transmitted Frames that are unacknowledged
when the command is actioned remain
unacknowledged;
4) the DISC command is used to perform a logical
disconnect, i.e. to inform the addressed combined
station that the transmitting combined station is
suspending operation. No information field shall be
permitted with the DISC command.
b) The unnumbered acknowledge response (UA) shall be
used by a combined station to acknowledge the receipt
and acceptance of an unnumbered command. Received
unnumbered commands are not actioned until the UA
response is transmitted. No information field shall be
permitted with the UA response.
c) Thc frame reject response (FRMR), employing the
information field described below, shall be used by a
combined slalion in the operational mode (ABM) to
report that one of the following conditions resultcd
from the receipt of a frame without an FCS error:
I) a command/response thal is invalid or not
implemented;
2) a frame with an information field lhal exceeds the
size of the buffer available;
3) a frame having an invalid N(R) count,
Note.- An invalid N(R) is a count which
points to an Iframe which has previously been
transmitted a d acknowledged or to an I-frame
which has ttot been transmitted and is not the next
sequential I-frame pending transmission.
d) The disconnected mode response (DM) shall be used
to report a non-operational status where the station is
logically disconnected from the link. No information
field shall be permitted with the DM response.
Note.- The DM response shall be sent to request the
remote combined station to issue a mode-setting command ol;
if sent in response to the reception of a mode-setting
command, to infonn the remote combined station that the
transmitting station is still in ADM and cannot actiorz the
mode-setiing command.
8.6.4.3 Exception condition reporting and recovery. This
section specifies the procedures that shall be employed to
effect recovery following the detection or occurrence of an
exception condition at the link level. Exception conditions
described are those situations that may occur as the result of
transnlission errors, station malfunction, or operational situations.
8.6.4.3.1 Busy condition. A busy condition occurs when
a station temporarily cannot receive or continue to receive
I-frames due to internal constraints, e.g. due to buffering limitations.
The busy condition shall be reported to the remote
combined station by the transmission of an RNR frame with
the N(R) number of the next I-frame thal is expected. I1 shall
be permissible for traffic pending transmission a1 the busy
station to be transmitted prior to or following the RNR.
Note.- The continued existence of a busy condition must
be reported by retransmission of RNR at each P/F frame
exchange.
8.6.4.3.1.1 Upon receipt of an RNR, a combined station
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
附件10--航空电信an10_v3_1ed_amend_71(65)
