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
a) requesting of the link layer, transmission of outgoing
packets;
b) receiving, from the link layer; incoming packets;
c) accepting requests fmm the IWF to initiate certain IS0
8208 protocol procedures including:
I) originate a virtual call,
2) accept a virtual call,
3) terminate a virtual call,
4) transfer data and interrupt information, and
5) re-initialize a logical channel.
d) report@ to the IWF the occurrence of certain IS0
8208 protocol events including:
I ) receipt of an incoming request to set up a virtual
call,
2) receipt of the acceptance of a virtual call setup,
3) termination of a virtual call,
4) receipt of data and interrupt information, and
5) re-initialization of a logical channel.
4.7.4.3.1.1 The IS0 8208 DCE shall accept all IS0
8208 packets from the IS0 8208 DTE without failure.
4.7.4.3.2 LOGICAL CHANNELS
Note.- Each virtual call and permanent virtual c i ~ u iits
assigned a logical channel identifier which is a number in the
range from I through 4 095. For each virtual call, a logical
channel identifier is assigned during the call setup phase from
a range of previously agreed-upon logical channel identaers.
For each permanent virtual circuit, a logical channel identifier
is assigned in agreement with the DTE. A DCEi use of
logical channels is agreed upon for a period of time with the
D TE.
4.7.4.3.3.1 The specifications and definitions in IS0
8208 shall apply for format definitions, diagnostic and cause
Note.- Tlze initiation of certain DCE procedures is codes, facility registration protocols (if used), and flow control
directed by elements outside the IS0 8208 DCE. Likewise, the on the IS0 8208 interface.
Part I Annex 10 - Aeronautical Telecommunications
Note 1.- The IS0 8208 DCE is defined as a state machine. 4.7.4.5 VC PRE-EMPTION
An IS0 8208 packet received jbm the DTE can cause state
transitions, as can a packet received from IWF The next state A logical channel of the lowest priority and the associated
transition (if any) that occurs when the DCE receives a packet virtual call shall be cleared as necessary to accept a request for
from the DTE is specified by Tables 4-29 to 4-34. These tables higher priority service.
are organized according to the hierarchy in Figure 4-31.
Note.- Logical channels and virtual calls have a priority
Note 2.- Upon receiving a packet, the action is classified level of 0 unless the IS0 8208 priority facility was invoked
as normal or erroneous under the entry "A =". The resulting during call set up.
state is shown under the entry, "S =".
4.7.4.3.3.2 If a state transition is specified, the action
taken shall be as specified in Tables 4-29 to 4-34.
4.7.5 Interworkig function
4.7.4.3.4 DISPOSITION OF PACKETS
When a packet is received from the DTE, the expressions in
parentheses in Tables 4-29 to 4-34 specify whether the packet
shall be forwarded or not forwarded to the IWE If no remark
in parentheses is listed or listed as not forwarded, then the
packet shall be discarded. The IS0 8208 DCE shall either
forward or not forward a packet from the IWF to the DTE in
a manner that is compatible with IS0 8208.
. 4.7.4.3.5 DIAGNOSTICAN D CAUSE CODES
For certain conditions, Tables 4-29 to 4-34 indicate a diagnostic
code that shall be included in the packet generated when
entering the state indicated. The term, "D =", shall define the
diagnostic code. When "A = DLAG, the action taken shall be
to generate an IS0 8208 diagnostic packet and transfer it to the
DTE; the diagnostic code indicated shall define the entry in the
diagnostic field of the packet. In the cause field of any packet
type, bit 8 of the cause field shalI always be set to 0, indicating
that the condition was recognized by the IS0 8208 interface.
Nore.- The state Tables 4-29 to 4-34 are defined so that
the SSNDPX and IS0 8208 DCE functions can operate simultaneously.
While asynchronous operation is a suitable implementation
strategy, it Is not a requirement for the SSNDPX
and IS0 8208 DCE operations.
4.7.4.3.6 . DCE TIMER
Note.- Under certain circumstances, the DTE must
respond to a packet issued from the DCE within a given rime.
4.7.4.3.6.1 Table 4-35 covers these circumstances and
the action that the DCE shall initiate upon the expiration of
that time.
The AES DCE shall support at least eight simultaneous,
independent logical channels.
4.7.5.1 SSNDPXIIWF INTERFACE
4.7.5.1.1 The IS0 8208 packets exchanged between the
IWF and the SSNDPX shall be as defined in Table 4-36.
4.7.5.1.2 INCOMINGCA LL
PACKET HANDUNG
The TWF shall forward the incoming call packet with the
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(42)
