📄 rfc2515.txt
字号:
described below.
7.1. Managing AAL5 in a Switch
Managing AAL5 in a switch involves:
(1) performance management of an AAL5 entity as
an internal resource in a switch
(2) performance management of AAL5 per virtual connection
Tesink Standards Track [Page 12]
RFC 2515 ATM Management Objects February 1999
AAL5 in a switch is modeled as shown in Figure 7 and 8. AAL5 will be
managed in a switch for only those virtual connections that carry
AAL5 and are terminated at the AAL5 entity in the switch. Note that,
the virtual channels within the ATM UNIs carrying AAL5 will be
switched by the ATM switching fabric (termed as ATM Entity in the
figure) to the virtual channels on a proprietary internal interface
associated with the AAL5 process (termed as AAL5 Entity in the
figure). Therefore, performance management of the AAL5 resource in
the switch will be modeled using the ifTable through an internal
(pseudo-ATM) virtual interface and the AAL5 performance management
per virtual connection will be supported using an additional AAL5
connection table in the ATM MIB. The association between the AAL5
virtual link at the proprietary virtual, internal interface and the
ATM virtual link at the ATM interface will be derived from the
virtual channel cross-connect table and the virtual channel link
table in the ATM MIB. Note that for the proprietary virtual interface
the traffic transmit and receive conventions in the virtual channel
link table are as follows:
Transmitting traffic: ATM Entity ---> AAL5 Entity
Receiving traffic: ATM Entity <--- AAL5 Entity
___________________________
| |
| ============= |
| | AAL5 | |
| | Entity | |
| ============= |
| | |
| -----Prop. Virtual Interface
| | |
| ============= |
| | ATM | |
| | Entity | |
| ============= |
|_____|__|__|__|__|_______|
| | | | |
---------------- ATM UNIs
| | | | |
| | | | |
v v v v v
Figure 7: Model of an AAL5 Entity in a Switch
Tesink Standards Track [Page 13]
RFC 2515 ATM Management Objects February 1999
__________________
| |
| AAL5 |
|________________|
| |
| Prop. Virtual |
| Interface |
|________________|
Figure 8: AAL5 Entity's Interface Stack in a Switch
7.2. Managing AAL5 in a Host
Managing AAL5 in a host involves managing the AAL5 sublayer interface
as shown in Figure 9 and 10. The AAL5 sublayer is stacked directly
over the ATM sublayer. The ifTable is applied to the AAL5 sublayer
as defined in Section 10.3.
___________________________
| |
| ============= |
| | AAL5 | |
| | Entity | |
| ============= |
| | ATM | |
| | Entity | |
| ============= |
|___________|_____________|
|
__|__ ATM UNI
|
|
v
Figure 9: Model of an AAL5 Entity in a Host
__________________
| |
| AAL5 |
|________________|
| |
| ATM Layer |
|________________|
| |
| Physical Layer|
|________________|
Figure 10: AAL5 Entity's Interface Stack in a Host
Tesink Standards Track [Page 14]
RFC 2515 ATM Management Objects February 1999
7.3. Support of AAL5 by ifTable
The AAL5 entity in an ATM device (e.g., switch or host) is managed
using the ifTable. There are additional counters specified for AAL5
than those specified in the ATM B-ICI document [21]. Specific
interpretations of ifTable for the AAL5 CPCS layer are as follows.
Object Use for AAL5 CPCS layer entity
====== ==============================
ifIndex Each AAL5 entity is represented by an ifEntry.
ifDescr Description of the AAL5 entity.
ifType The value that is allocated for AAL5 is 49.
ifMtu Set to the largest PDU size for the
AAL5 CPCS layer that can be processed
by the AAL5 entity.
ifSpeed Set to 0.
ifPhysAddress An octet string of zero length.
ifAdminStatus See [17].
ifOperStatus Assumes the value down(2) if the AAL5
layer is down.
ifLastChange See [17].
ifInOctets The number of received AAL5 CPCS PDU octets.
ifOutOctets The number of AAL5 CPCS PDU octets
transmitted.
ifInUcastPkts The number of received AAL5 CPCS PDUs passed
to a higher-layer.
ifOutUcastPkts The number of AAL5 CPCS PDUs received from a
higher-layer for transmission.
[Note: The number of AAL5 PDUs actually
transmitted is the number received from a
higher-layer for transmission minus any which
are counted by ifOutErrors and ifOutDiscards.]
Tesink Standards Track [Page 15]
RFC 2515 ATM Management Objects February 1999
ifInErrors Number of errored AAL5 CPCS PDUs received.
The types of errors counted include CRC-32 errors,
SAR time-out errors, and oversized SDU errors.
ifInUnknownProtos Set to 0.
ifInDiscards Number of received AAL5 CPCS PDUs discarded.
Possible reason may be input buffer overflow.
ifOutErrors Number of AAL5 CPCS PDUs that could not
be transmitted due to errors.
ifOutDiscards Number of AAL5 CPCS PDUs received for
transmission that are discarded.
Possible reason may be output buffer
overflow.
ifInMulticastPkts Set to 0.
ifInBroadcastPkts Set to 0.
ifOutMulticastPkts Set to 0.
ifOutBroadcastPkts Set to 0.
ifName Textual name (unique on this system) of the
AAL5 entity or an octet string of zero length.
ifHighSpeed Set to 0.
ifConnectorPresent Set to false (2).
ifPromiscuousMode Set to false(2).
ifLinkUpDownTrapEnable Default is disabled (2).
ifAlias The non-volatile 'alias' name for the interface
as specified by a network manager.
7.4. Support of Proprietary Virtual Interface by ifTable
Specific interpretations of ifTable for the proprietary virtual,
internal interface associated with an AAL5 entity in an ATM switch
are as follows.
Tesink Standards Track [Page 16]
RFC 2515 ATM Management Objects February 1999
Object Use for proprietary virtual, internal interface
associated with AAL entities
====== ===============================================
ifIndex Each proprietary virtual, internal interface
associated with AAL entities is represented by an
ifEntry.
ifDescr Description of the proprietary virtual, internal
interface associated with AAL entities.
ifType The value that is allocated for proprietary
virtual, internal interface is 53.
ifSpeed See [17]. Set to 0 if the speed is not
known.
ifPhysAddress See [17]. An octet string of zero length
if no address is used for this interface.
ifAdminStatus See [17].
ifOperStatus See [17].
ifLastChange See [17].
ifName Textual name (unique on this system) of the
interface or an octet string of zero length.
ifHighSpeed See [17]. Set to 0 if the speed is not known.
ifConnectorPresent Set to false (2).
ifLinkUpDownTrapEnable Default is disabled (2).
ifAlias The non-volatile 'alias' name for the interface
as specified by a network manager.
7.5. AAL5 Connection Performance Statistics Table
An AAL5 connection table is used to provide AAL5 performance
information for each AAL5 virtual connection that is terminated at
the AAL5 entity contained within an ATM switch or host.
Tesink Standards Track [Page 17]
RFC 2515 ATM Management Objects February 1999
8. ILMI MIBs and the ATM Managed Objects
The ILMI MIBs are specified by the ATM Forum as a set of several
MIBs, all currently defined in the ILMI Specification [23]. The ILMI
protocols and MIBs allow two connected ATM Interface Management
Entities (IMEs) to exchange bi-directional parameters, mainly to
facilitate auto-configuration between ATM peer entities. The support
of the ATM management functions by the ILMI MIBs and those contained
in this memo are compared in Table 1. In this table, "yes" in the
"ILMI MIBs" column indicates that the management functions are
supported by the ILMI MIBs. The parenthesized numbers in the "This
memo" column correspond to the sets of tables enumerated in Section
6.2.
For that subset of management information which the ILMI MIBs and
this memo have in common, every effort has been made to retain
identical semantics and syntax, even though the MIB objects are
identified using different OBJECT IDENTIFIERs.
Table 1 - Structuring of ATM Managed Objects
______________________________________________________________
| |This |ILMI|
ATM Mgmt.Inf. |ATM Managed Objects |memo |MIBs|
______________|_________________________________|_______|____|
Local Interface Information:
_____________________________________________________________
ATM interface:| (1) port identifier |ATM MIB| |
physical layer| (2) physical transmission types | (1)*|yes |
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -