RFC 4546
Radio Frequency (RF) Interface Management Information Base for Data over Cable Service Interface Specifications (DOCSIS) 2.0 Compliant RF Interfaces
Network Working Group D. Raftus Request for Comments: 4546 ATI Technologies, Inc. Obsoletes: 2670 E. Cardona Category: Standards Track CableLabs June 2006 Radio Frequency (RF) Interface Management Information Base for Data over Cable Service Interface Specifications (DOCSIS) 2.0 Compliant RF Interfaces Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. This document revises and obsoletes RFC 2670. Please see Section 5.3 for a description of the changes from RFC 2670. Copyright Notice Copyright (C) The Internet Society (2006).Abstract
This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it defines a set of managed objects for Simple Network Management Protocol (SNMP) based management of the Radio Frequency (RF) interfaces for systems compliant with the Data Over Cable Service Interface Specifications (DOCSIS).Table of Contents
1. The Internet-Standard Management Framework ......................2 2. Glossary ........................................................3 2.1. Baseline Privacy ...........................................3 2.2. CATV .......................................................3 2.3. Channel ....................................................3 2.4. CM or Cable Modem ..........................................3 2.5. CMTS or Cable Modem Termination System .....................3 2.6. Codeword ...................................................4 2.7. Data Packet ................................................4 2.8. dBmV .......................................................4 2.9. DOCSIS .....................................................4
2.9.1. DOCSIS 1.0 ..........................................4
2.9.2. DOCSIS 1.1 ..........................................4
2.9.3. DOCSIS 2.0 ..........................................4
2.10. Downstream ................................................5
2.11. Euro-DOCSIS ...............................................5
2.12. Head-end ..................................................5
2.13. MAC Packet ................................................5
2.14. MCNS ......................................................5
2.15. Mini-slot .................................................5
2.16. QPSK (Quadrature Phase Shift Keying) ......................5
2.17. QAM (Quadrature Amplitude Modulation) .....................5
2.18. RF ........................................................5
2.19. Symbol-times ..............................................5
2.20. Upstream ..................................................6
3. Overview ........................................................6
3.1. Textual Conventions ........................................6
3.1.1. Textual Conventions in RFC 2670 .....................6
3.1.2. Textual Conventions in RFC 4546 .....................6
3.2. Structure of the MIB .......................................6
3.2.1. docsIfBaseObjects ...................................7
3.2.2. docsIfCmObjects .....................................7
3.2.3. docsIfCmtsObjects ...................................8
3.2.4. Relationship to the Interfaces MIB Module ...........8
3.2.5. Offline Upstream Parameters Handling ...............22
4. Definitions ....................................................24
5. Revision History ..............................................134
5.1. Scope ....................................................134
5.2. Extension ................................................134
6. Security Considerations .......................................134
7. Management Interoperability of DOCSIS 1.0, 1.1, and 2.0 .......136
8. References ....................................................136
8.1. Normative References .....................................136
8.2. Informative References ...................................137
1. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current
Internet-Standard Management Framework, please refer to section 7 of
RFC 3410 [RFC3410].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally
accessed through the Simple Network Management Protocol (SNMP).
Objects in the MIB are defined using the mechanisms defined in the
Structure of Management Information (SMI). This memo specifies a MIB
module that is compliant to the SMIv2, which is described in STD 58,
RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] STD 58, RFC 2580
[RFC2580].
2. Glossary
The terms in this document are derived either from normal cable system usage, or from the documents associated with the Data Over Cable Service Interface Specification process.2.1. Baseline Privacy
Security interface specification, designed for DOCSIS-compliant cable data systems, that ensures device authentication data confidentiality in the CATV plant. See [BPI] and [BPIPLUS].2.2. CATV
Originally "Community Antenna Television", it now refers to any cable or hybrid fiber and cable system used to deliver video signals to a community.2.3. Channel
A specific frequency allocation with an RF medium, specified by channel width in Hertz (cycles per second) and by center frequency. Within the US Cable Systems, upstream channels are generally allocated from the 5-42MHz range while downstream channels are generally allocated from the 50-750MHz range, depending on the capabilities of the given system. The typical broadcast channel width in the US is 6MHz. Upstream channel widths for DOCSIS vary. For European cable systems, upstream channels vary by country. The upper edge of upstream channel allocations varies between 25 MHz to 65 MHz, and the lower edge of downstream channel allocations varies between 47 MHz and 87.5 MHz. The typical broadcast channel width in Europe is 8MHz. The actual parameters are of concern to systems deploying Euro-DOCSIS technology. The downstream channels conform to the requirements of ITU-T Recommendation J.83 [ITU-T_J.83]2.4. CM or Cable Modem
A CM acts as a "slave" station in a DOCSIS-compliant cable data system.2.5. CMTS or Cable Modem Termination System
A generic term covering a cable bridge or cable router in a head-end. A CMTS acts as the master station in a DOCSIS-compliant cable data system. It is the only station that transmits downstream, and it
controls the scheduling of upstream transmissions by its associated CMs.2.6. Codeword
A characteristic of the Forward Error Correction scheme, used above the RF media layer. See "Data-Over-Cable Service Interface Specifications: Radio Frequency Interface Specification SP-RFIv2.0-I10-051209".2.7. Data Packet
The payload portion of the MAC Packet.2.8. dBmV
A measure of RF signal voltage amplitude, whose power level is determined by the characteristic impedance. A zero dB signal power is equivalent to 48.75 dBmV signal amplitude in a 75 Ohm system.2.9. DOCSIS
"Data Over Cable Service Interface Specification". A term referring to the ITU-T J112 [ITU-T_J.112] Annex B standard for cable modem systems.2.9.1. DOCSIS 1.0
Cable modem systems that are CM/CMTS compliant to requirements in [RFI1.0]. A common reference to DOCSIS 1.0 in this document is the upstream channel queuing mechanism, known as Class of Service (COS).2.9.2. DOCSIS 1.1
Cable modem systems that are CM/CMTS compliant to requirements in [ITU-T_J.112]. DOCSIS 1.1 references in this document are in part associated with the upstream and downstream Quality of Service (QOS). The term DOCSIS 1.x is used in this document to refer to both DOCSIS 1.0 and DOCSIS 1.1.2.9.3. DOCSIS 2.0
Cable modem systems that are CM/CMTS compliant to requirements in [ITU-T_J.122]. DOCSIS 2.0 corresponds to the second generation of radio-frequency interface specifications of DOCSIS.
2.10. Downstream
The direction from the head-end towards the subscriber.2.11. Euro-DOCSIS
Cable modem systems CM/CMTS that conform to the European spectrum lineup and are compliant to requirements of Annex F in [ITU-T_J.122].2.12. Head-end
The origination point in most cable systems of the subscriber video signals. Generally also the location of the CMTS equipment.2.13. MAC Packet
A DOCSIS PDU.2.14. MCNS
"Multimedia Cable Network System". Generally replaced in usage by DOCSIS.2.15. Mini-slot
In general, an interval of time that is allocated by the CMTS to a given CM for that CM to transmit in an upstream direction. See [ITU-T_J.122]2.16. QPSK (Quadrature Phase Shift Keying)
A particular modulation scheme on an RF medium. See [Proakis00].2.17. QAM (Quadrature Amplitude Modulation)
A particular modulation scheme on RF medium. Usually expressed with a number indicating the size of the modulation constellation (e.g., 16 QAM). See [Proakis00].2.18. RF
Radio Frequency.2.19. Symbol-times
A characteristic of the RF modulation scheme. See [ITU-T_J.122].
2.20. Upstream
The direction from the subscriber towards the head-end.3. Overview
This MIB module provides a set of objects required for the management of DOCSIS-compliant Cable Modem (CM) and Cable Modem Termination System (CMTS) RF interfaces. The specification is derived in part from the parameters and protocols described in [ITU-T_J.122]. In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in [RFC2119].3.1. Textual Conventions
This MIB module defines new textual conventions for CM and CMTS indications of DOCSIS 2.0 RFI capabilities, configuration, usage, and backward compatible modes of operation, as defined in [RFI2.0]. With the same purpose, there are some textual conventions that represent capabilities and modes of operation of [RFI1.1] that are not covered by RFC 2670, and are managed proprietarily in the DOCSIS OSSI 1.1 specification [OSSI1.1].3.1.1. Textual Conventions in RFC 2670
RFC 2670 defined two textual conventions, TenthdBmV and TenthdB, which are power measurement representations.3.1.2. Textual Conventions in RFC 4546
This MIB module defines the textual convention DocsisUpstreamType to represent the DOCSIS 1.0 [RFI1.0] and DOCSIS 2.0 [RFI2.0] upstream burst modulation profiles types. This MIB module defines the textual conventions DocsisVersion and DocsisQosVersion to represent the DOCSIS 1.0 [RFI1.0] and DOCSIS 1.1 [RFI1.1] COS/QOS capabilities and modes of operation.3.2. Structure of the MIB
This MIB module is structured as three groups: o Management information pertinent to both Cable Modem (CM) and Cable Modem Termination System (CMTS) (docsIfBaseObjects).
o Management information pertinent to Cable Modem only
(docsIfCmObjects).
o Management information pertinent to Cable Modem Termination System
only (docsIfCmtsObjects).
Tables within each of these groups cover different functions; e.g.,
upstream queue services, channel characteristics, MAC layer
management, etc. Rows created automatically (e.g., by the device
according to the hardware configuration) may and generally will have
a mixture of configuration and status objects within them. Rows that
are meant to be created by the management station are generally
restricted to configuration (read-create) objects.
3.2.1. docsIfBaseObjects
docsIfDownstreamChannelTable - This table describes the existing
downstream channels for a CMTS and the received downstream channel
for a CM.
docsIfUpstreamChannelTable - This table describes the existing
upstream channels for a CMTS and the current upstream transmission
channel for a CM.
docsIfQosProfileTable - This table describes the valid Quality of
Service profiles for the cable data system.
docsIfSignalQualityTable - This table is used to monitor RF signal
quality characteristics of received signals.
docsIfDocsisBaseCapability - This object is used to indicate the
highest level of DOCSIS version a cable device can support.
3.2.2. docsIfCmObjects
docsIfCmMacTable - This table is used to monitor the DOCSIS MAC
interface and can be considered an extension to the ifEntry.
docsIfCmStatusTable - This table maintains a number of status objects
and counters for cable modems. There is a comparable table at the
CMTS, docsIfCmtsCmStatusTable, which maintains similar counters from
the CMTS point of view.
docsIfCmServiceTable - This table describes the upstream service
queues available at this CM. There is a comparable table at the
CMTS, docsIfCmtsServiceEntry, which describes the service queues from
the point of view of the CMTS.
3.2.3. docsIfCmtsObjects
docsIfCmtsMacTable - Describes the attributes of each CMTS MAC interface. docsIfCmtsStatusTable - This table provides a set of aggregated counters that roll-up values and events that occur on the underlying sub-interfaces. docsIfCmtsCmStatusTable - This table is used to hold information about known (i.e., ranging, registered, and/or previously online) cable modems on the system serviced by this CMTS. docsIfCmtsServiceTable - This table provides access to the information related to upstream service queues. docsIfCmtsModulationTable - This table allows control over the modulation profiles for RF channels associated with this CMTS. docsIfCmtsMacToCmTable - This table allows fast access into the docsIfCmtsCmTable via a MAC address (of the CM) interface. docsIfCmtsChannelUtilizationTable - This table provides statistical load usage data for attached upstream and downstream physical channels. docsIfCmtsDownChannelCounterTable - This table provides statistical data for attached downstream channels, appropriate as input for load usage calculations. docsIfCmtsUpChannelCounterTable - This table provides statistical data for attached upstream channels, appropriate as input for load usage calculations.3.2.4. Relationship to the Interfaces MIB Module
This section clarifies the relationship of this MIB module to the Interfaces MIB [RFC2863]. Several areas of correlation are addressed in the following subsections. The implementer is referred to the Interfaces MIB document in order to understand the general intent of these areas.3.2.4.1. Layering Model
An instance of ifEntry exists for each RF downstream interface, for each RF upstream interface, for each upstream logical Channel, and for each RF MAC layer.
The ifStackTable [RFC2863] MUST be implemented to identify the relationships among sub-interfaces. The following example illustrates a CMTS MAC interface with one downstream and two upstream interfaces. | <== to network layer +------------------ --+-------------------------------+ | RF MAC | +--+------------------+------------------------+------+ | | | +-------+-----+ +------+------+ +------+------+ | Downstream1 | | Upstream1 | | Upstream2 | | | | | | | +-------------+ ++-----------++ ++-----------++ | | | | +----+----+ +----+----+ +----+----+ +----+----+ | Ch-1 | | Ch-2 | | Ch-1 | | Ch-2 | |(A/TDMA) | |(S-CDMA) | |(A/TDMA) | |(S-CDMA) | +---------+ +---------+ +---------+ +---------+ Figure 1 As can be seen from this example, the RF MAC interface is layered on top of the downstream and upstream interfaces, and the RF upstream interface is layered on top of an upstream logical channel. In this example, the assignment of index values could be as follows: ifIndex ifType Description 2 docsCableMaclayer(127) CATV MAC Layer 3 docsCableDownstream(128) CATV Downstream interface 4 docsCableUpstream(129) CATV Upstream interface 5 docsCableUpstream(129) CATV Upstream interface 6 docsCableUpstreamChannel(205) CATV Upstream Channel 7 docsCableUpstreamChannel(205) CATV Upstream Channel 8 docsCableUpstreamChannel(205) CATV Upstream Channel 9 docsCableUpstreamChannel(205) CATV Upstream Channel Figure 2
The corresponding ifStack entries would then be: | IfStackHigherLayer | ifStackLowerLayer | | 0 | 2 | | 2 | 3 | | 2 | 4 | | 2 | 5 | | 4 | 6 | | 4 | 7 | | 5 | 8 | | 5 | 9 | | 3 | 0 | | 6 | 0 | | 7 | 0 | | 8 | 0 | | 9 | 0 | Figure 3 The same interface model can also be used in Telephony or Telco Return systems. A pure Telco Return system (Cable Modem, as well as Cable Modem Termination System) would not have upstream cable channels, only downstream cable channels. Systems supporting both Telco Return and cable upstream channels can use the above model without modification. Telco Return upstream channel(s) management is outside the scope of this document.3.2.4.2. Virtual Circuits
This medium does not support virtual circuits, and this area is not applicable to this MIB module.3.2.4.3. ifTestTable
The ifTestTable is optional for DOCSIS CM/CMTS implementations, but is not specifically influenced by the RF MIB.3.2.4.4. ifRcvAddressTable
The ifRcvAddressTable is optional for DOCSIS CM/CMTS implementations, but is not specifically influenced by the RF MIB.
3.2.4.5. ifEntry
This section documents only the differences from the requirements specified in the Interfaces MIB module. See that MIB module for columns omitted from the descriptions below.3.2.4.5.1. ifEntry for Downstream Interfaces
The ifEntry for downstream interfaces supports the ifGeneralInformationGroup and the ifPacketGroup of the Interfaces MIB module. This is an output-only interface at the CMTS, and all input status counters -- ifIn* -- will return zero. This is an input-only interface at the CM, and all output status counters -- ifOut* -- will return zero.3.2.4.5.1.1. ifEntry for Downstream Interfaces in Cable Modem Termination System ifTable Comments ============== =========================================== ifIndex Each CATV Downstream interface is represented by an ifEntry. ifType The IANA value of docsCableDownstream(128). ifSpeed Return the speed of this downstream channel. The returned value is the raw bandwidth in bits/s of this interface. This is the symbol rate multiplied with the number of bits per symbol. ifHighSpeed Return the speed of this downstream channel. The returned value is the raw bandwidth in megabits/s of this interface. This is the symbol rate multiplied with the number of bits per symbol. ifPhysAddress Return the zero-length OCTET STRING. ifAdminStatus The administrative status of this interface. ifOperStatus The current operational status of this interface. ifMtu The size of the largest frame that can be sent on this interface, specified in octets. The value includes the length of the MAC header. ifInOctets ifHCInOctets Return zero.
ifInUcastPkts
ifHCInUcastPkts Return zero.
ifInMulticastPkts
ifHCInMulticastPkts
Return zero.
ifInBroadcastPkts
ifHCInBroadcastPkts
Return zero.
ifInDiscards Return zero.
ifInErrors Return zero.
ifInUnknownProtos Return zero.
ifOutOctets
ifHCOutOctets The total number of octets transmitted on this
interface. This includes MAC packets as well as
data packets, and includes the length of the MAC
header.
ifOutUcastPkts
ifHCOutUcastPkts The number of unicast packets transmitted on this
interface. This includes MAC packets as well as
data packets.
ifOutMulticastPkts
ifHCOutMulticastPkts
Return the number of multicast packets
transmitted on this interface.
This includes MAC packets as well as data
packets.
ifOutBroadcastPkts
ifHCOutBroadcastPkts
Return the number of broadcast packets transmitted
on this interface. This includes MAC packets as
well as data packets.
ifOutDiscards The total number of outbound packets which
were discarded. Possible reasons are:
buffer shortage.
ifOutErrors The number of packets that could not be
transmitted due to errors.
ifPromiscuousMode Return false.
3.2.4.5.1.2. ifEntry for Downstream Interfaces in Cable Modem ifTable Comments ============== =========================================== ifIndex Each CATV Downstream interface is represented by an ifEntry. ifType The IANA value of docsCableDownstream(128). ifSpeed Return the speed of this downstream channel. The returned value the raw bandwidth in bits/s of this interface. This is the symbol rate multiplied with the number of bits per symbol. ifHighSpeed Return the speed of this downstream channel. The returned value the raw bandwidth in megabits/s of this interface. This is the symbol rate multiplied with the number of bits per symbol. ifPhysAddress Return the zero-length OCTET STRING. ifAdminStatus The administrative status of this interface. ifOperStatus The current operational status of this interface. ifMtu The size of the largest frame that can be received from this interface, specified in octets. The value includes the length of the MAC header. ifInOctets ifHCInOctets The total number of octets received on this interface. This includes data packets as well as MAC packets, and includes the length of the MAC header. ifInUcastPkts ifHCInUcastPkts The number of unicast packets received on this interface. This includes data packets as well as MAC packets. ifInMulticastPkts ifHCInMulticastPkts Return the number of multicast packets received on this interface. This includes data packets as well as MAC packets.
ifInBroadcastPkts
ifHCInBroadcastPkts
Return the number of broadcast packets received
on this interface. This includes data packets
as well as MAC packets.
ifInDiscards The total number of received packets that have
been discarded.
The possible reasons are: buffer shortage.
ifInErrors The number of inbound packets that contained
errors preventing them from being deliverable
to higher layers.
Possible reasons are: MAC FCS error.
ifInUnknownProtos The number of frames with an unknown packet type.
These are MAC frames with an unknown packet type.
ifOutOctets Return zero.
ifHCOutOctets
ifOutUcastPkts Return zero.
ifHCOutUcastPkts
ifOutMulticastPkts
ifHCOutMulticastPkts
Return zero.
ifOutBroadcastPkts
ifHCOutBroadcastPkts
Return zero.
ifOutDiscards Return zero.
ifOutErrors Return zero.
ifPromiscuousMode Refer to the Interfaces MIB.
3.2.4.5.2. ifEntry for Upstream Interfaces
Each supported interface of the type docsCableUpstream(129) must have
a corresponding ifEntry. The ifEntry for upstream interfaces
supports the ifGeneralInformationGroup and the ifPacketGroup of the
Interfaces MIB. This is an input-only interface at the CMTS, and all
output status counters -- ifOut* -- will return zero. This is an
output only interface at the CM, and all input status counters --
ifIn* -- will return zero.
3.2.4.5.2.1. ifEntry for Upstream Interfaces in Cable Modem Termination System ifTable Comments ============== =========================================== ifIndex Each RF Cable Upstream interface is represented by an ifEntry. ifType The IANA value of docsCableUpstream (129). ifSpeed Return the maximum channel throughput (not payload throughput) supported by the interface. The maximum throughput is calculated for the case where upstream channels are configured to maximize interface throughput. ifHighSpeed Return the maximum channel throughput (not payload throughput) supported by the interface. The maximum throughput is calculated for the case where upstream channels are configured to maximize interface throughput. Units for this object are (1/1 000 000) * IfSpeed. ifPhysAddress Return the zero-length OCTET STRING. ifAdminStatus The administrative status of this interface. ifOperStatus The current operational status of this interface. This reflects the total status of all the channels under this interface. So if at least one channel has a physical connection this interface has connection. ifMtu The size of the largest frame that can be transmitted on this interface, specified in octets. The value includes the length of the MAC header. This is the maximum of all the ifMtu of all the channels under this interface. ifInOctets ifHCInOctets The total (sum) number of octets received on all the upstream channels under this interface. This includes data packets as well as MAC packets, and includes the length of the MAC header.
ifInUcastPkts
ifHCInUcastPkts The total number of unicast packets received on
all the upstream channels under this
interface. This includes data packets as well as
MAC packets.
ifInMulticastPkts
ifHCInMulticastPkts
Return the total number of multicast packets
received on all the upstream channels under this
interface. This includes data packets as well as
MAC layer packets.
ifInBroadcastPkts
ifHCInBroadcastPkts
Return the total number of broadcast packets
received on all the upstream channels under this
interface. This includes data packets as well as
MAC packets.
ifInDiscards The total number of received packets that have
been discarded on all the upstream channels under
this interface.
The possible reasons are: buffer shortage.
ifInErrors The total number of inbound packets that contained
errors preventing them from being deliverable
to higher layers.
Possible reasons are: MAC FCS error.
ifInUnknownProtos The total number of frames with an unknown packet
type. These are MAC frames with an unknown packet
type.
ifOutOctets Return zero.
ifHCOutOctets
ifOutUcastPkts Return zero.
ifHCOutOctets
ifOutMulticastPkts
ifHCOutMulticastPkts
Return zero.
ifOutBroadcastPkts
ifHCOutBroadcastPkts
Return zero.
ifOutDiscards Return zero. ifOutErrors Return zero.3.2.4.5.2.2. ifEntry for Upstream Interfaces in Cable Modem ifTable Comments ============== =========================================== ifIndex Each RF Cable Upstream interface is represented by an ifEntry. ifType The IANA value of docsCableUpstream (129). ifSpeed Return the speed of this upstream interface. The returned value is the raw bandwidth in bits/s of this interface. ifHighSpeed Return the speed of this upstream interface. The returned value is the raw bandwidth in megabits/s of this interface. ifPhysAddress Return the zero-length OCTET STRING. ifAdminStatus The administrative status of this interface. ifOperStatus The current operational status of this interface. ifMtu The size of the largest frame that can be transmitted on this interface, specified in octets. The value includes the length of the MAC header. ifInOctets Return zero. ifHCInOctets ifInUcastPkts Return zero. ifHCInUcastPkts ifInMulticastPkts ifHCInMulticastPkts Return zero. ifInBroadcastPkts ifHCInBroadcastPkts Return zero. ifInDiscards Return zero.
ifInErrors Return zero.
ifInUnknownProtos Return zero.
ifOutOctets
ifHCOutOctets The total number of octets transmitted on this
interface. This includes MAC packets as well as
data packets, and includes the length of the MAC
header.
ifOutUcastPkts
ifHCOutUcastPkts The number of unicast packets transmitted on this
interface. This includes MAC packets as well as
data packets.
ifOutMulticastPkts
ifHCOutMulticastPkts
Return the number of multicast packets transmitted
on this interface.
This includes MAC packets as well as data packets.
ifOutBroadcastPkts
ifHCOutBroadcastPkts
Return the number of broadcast packets transmitted
on this interface.
This includes MAC packets as well as data packets.
ifOutDiscards The total number of outbound packets that
were discarded. Possible reasons are:
buffer shortage.
ifOutErrors The number of packets that could not be
transmitted due to errors.
ifPromiscuousMode Return false.
3.2.4.5.3. ifEntry for Upstream Channels
Each supported channel of the type docsCableUpstreamChannel(205) must
have a corresponding ifEntry.
The ifEntry for upstream channels supports the
ifGeneralInformationGroup and the ifPacketGroup of the Interfaces
MIB. This is an input only interface at the CMTS and all output
status counters -- ifOut* -- will return zero. DOCSIS CMs are not
required to support logical upstream channels.
3.2.4.5.3.1. ifEntry for Upstream Channels in Cable Modem Termination System ifTable Comments ============== =========================================== ifIndex Each RF Cable Upstream channel is represented by an ifEntry. ifType The IANA value of docsCableUpstreamChannel (205). ifSpeed Return the speed of this upstream channel. The returned value is the raw bandwidth in bits/s of this channel. ifHighSpeed Return the speed of this upstream channel. The returned value is the raw bandwidth in megabits/s of this channel. ifPhysAddress Return the zero-length OCTET STRING. ifAdminStatus The administrative status of this interface. ifOperStatus The current operational status of this interface. ifMtu The size of the largest frame that can be received on this interface, specified in octets. The value includes the length of the MAC header. ifInOctets The total number of octets received on this interface. This includes data packets as well as MAC packets, and includes the length of the MAC header. ifInUcastPkts ifHCInUcastPkts The number of unicast packets received on this interface. This includes data packets as well as MAC packets. ifInMulticastPkts ifHCInMulticastPkts Return the number of multicast packets received on this interface. This includes data packets as well as MAC layer packets.
ifInBroadcastPkts
ifHCInBroadcastPkts
Return the number of broadcast packets received
on this interface. This includes data packets
as well as MAC packets.
ifInDiscards The total number of received packets that have
been discarded.
The possible reasons are: buffer shortage.
ifInErrors The number of inbound packets that contained
errors preventing them from being deliverable
to higher layers.
Possible reasons are: MAC FCS error.
ifInUnknownProtos The number of frames with an unknown packet type.
These are MAC frames with an unknown packet type.
ifOutOctets Return zero.
ifHCOutOctets
ifOutUcastPkts Return zero.
ifHCOutUcastPkts
ifOutMulticastPkts
ifHCOutMulticastPkts
Return zero.
ifOutBroadcastPkts
ifHCOutBroadcastPkts
Return zero.
ifOutDiscards Return zero.
ifOutErrors Return zero.
3.2.4.5.4. ifEntry for the MAC Layer
The ifEntry for the MAC Layer supports the ifGeneralInformationGroup
and the ifPacketGroup of the Interfaces MIB. This interface provides
an aggregate view of status for the lower level downstream and
upstream interfaces.
ifTable Comments
============== ===========================================
ifIndex Each RF Cable MAC layer entity is represented
by an ifEntry.
ifType The IANA value of docsCableMaclayer(127).
ifSpeed Return zero.
ifPhysAddress Return the physical address of this interface.
ifAdminStatus The administrative status of this interface.
ifOperStatus The current operational status of the MAC
layer interface.
ifHighSpeed Return zero.
ifMtu Return 1500.
ifInOctets
ifHCInOctets The total number of data octets received on this
interface, targeted for upper protocol layers.
ifInUcastPkts
ifHCInUcastPkts The number of unicast packets received on this
interface, targeted for upper protocol layers.
ifInMulticastPkts
ifHCInMulticastPkts
Return the number of multicast packets received
on this interface, targeted for upper protocol
layers.
ifInBroadcastPkts
ifHCInBroadcastPkts
Return the number of broadcast packets received
on this interface, targeted for upper protocol
layers.
ifInDiscards The total number of received packets that have
been discarded.
The possible reasons are: buffer shortage.
ifInErrors The number of inbound packets that contained
errors preventing them from being deliverable
to higher layers.
Possible reasons are: data packet FCS error,
invalid MAC header.
ifInUnknownProtos The number of frames with an unknown packet type.
This is the number of data packets targeted for
upper protocol layers with an unknown packet type.
ifOutOctets The total number of octets, received from upper
ifHCOutOctets protocol layers and transmitted on this interface.
ifOutUcastPkts
ifHCOutUcastPkts The number of unicast packets, received from upper
protocol layers and transmitted on this interface.
ifOutMulticastPkts
ifHCOutMulticastPkts
Return the number of multicast packets received
from upper protocol layers and transmitted on this
interface.
ifOutBroadcastPkts
ifHCOutBroadcastPkts
Return the number of broadcast packets received
from upper protocol layers and transmitted on this
interface.
ifOutDiscards The total number of outbound packets that
were discarded. Possible reasons are:
buffer shortage.
ifOutErrors The number of packets that could not be
transmitted due to errors.
ifPromiscuousMode Refer to the Interfaces MIB.
3.2.5. Offline Upstream Parameters Handling
3.2.5.1. Overview
This section describes the offline configuration of the DOCSIS 2.0
upstream logical interface parameters. The purpose of this feature
is to guarantee that upstream logical interface parameters (such as
modulation profile, channel type, mini-slot size, and SCDMA
attributes) are consistent prior to committing changes to an active
upstream logical interface. This mechanism can reduce possible
downtime of the upstream interface by minimizing SNMP SET operations
to in-service upstream interfaces. This mechanism is supported by
CMTSs and is not applicable to CMs.
3.2.5.2. Operation
This mechanism uses three upstream channel MIB objects defined for
DOCSIS 2.0 CMTS implementations:
docsIfUpChannelStatus - The RowStatus object for the creation of
temporary interfaces in the upstream interface table. A temporary
entry is used to modify, validate, and commit upstream parameters of
a physical interface. In the CMTS, a physical upstream interface
refers to an upstream logical channel interface.
docsIfUpChannelCloneFrom - This MIB object associates a physical
interface with a temporary interface for the purpose of updating the
upstream parameters of the physical interface.
docsIfUpChannelUpdate - This MIB object is the commit object that
transfers the validated upstream parameters from the temporary
interface to the physical interface.
The offline upstream parameters handling operation is as follows:
o A temporary interface is created in which docsIfUpChannelStatus is
set to 'createAndWait', which turns the new create entry status to
'notReady'.
o A SET to docsIfUpChannelCloneFrom in the temporary interface to
the physical interface ifIndex value performs two actions:
* Creates the association of the physical interface to the
temporary interface.
* Copies the original upstream parameters from the physical
interface to the temporary interface, which turns its status to
'notInService'.
o The operator modifies the temporary interface parameters to the
desired values.
o At this point, a SET to 'active' to the RowStatus of the temporary
interface is successful if all parameters in the temporary
interface are valid for the associated physical interface;
otherwise, the temporary entry remains with status 'notInservice',
and the SET returns the error 'commitFailed'.
o When the temporary interface status is 'active', a SET to
docsIfUpChannelUpdate to 'true' transfers the temporary interface
parameters values to the physical interface.
o After completion of the update operations, the temporary interface
is destroyed, setting the docsIfUpChannelStatus to 'destroy'.
3.2.5.3. Relation of docsIfUpChannelStatus and ifMib
The main purpose of docsIfUpChannelStatus is the creation of temporary interfaces for offline handling of the configuration of physical interfaces; it does not manage the creation or control of physical interfaces. To maintain a consistent operation and status report of interfaces, this object does not manage the administrative and operational status of physical interfaces.
(page 24 continued on part 2)
