DESCRIPTION
"A collection of objects providing remote
configuration and statistics information."
::= { ds1Groups 3 }
ds1DeprecatedGroup OBJECT-GROUP
OBJECTS { dsx1IfIndex,
dsx1FracIndex,
dsx1FracNumber,
dsx1FracIfIndex }
STATUS deprecated
DESCRIPTION
"A collection of obsolete objects that may be
implemented for backwards compatibility."
::= { ds1Groups 4 }
ds1NearEndOptionalConfigGroup OBJECT-GROUP
OBJECTS { dsx1LineStatusLastChange,
dsx1LineStatusChangeTrapEnable }
STATUS current
DESCRIPTION
"A collection of objects that may be implemented
on DS1 and DS2 interfaces."
::= { ds1Groups 5 }
ds1DS2Group OBJECT-GROUP
OBJECTS { dsx1LineIndex,
dsx1LineType,
dsx1LineCoding,
dsx1SendCode,
dsx1LineStatus,
dsx1SignalMode,
dsx1TransmitClockSource,
dsx1Channelization }
STATUS current
DESCRIPTION
"A collection of objects providing information
about DS2 (6,312 kbps) and E2 (8,448 kbps)
systems."
::= { ds1Groups 6 }
ds1TransStatsGroup OBJECT-GROUP
OBJECTS { dsx1CurrentESs,
dsx1CurrentSESs,
dsx1CurrentUASs,
dsx1IntervalESs,
dsx1IntervalSESs,
dsx1IntervalUASs,
dsx1TotalESs,
dsx1TotalSESs,
dsx1TotalUASs }
STATUS current
DESCRIPTION
"A collection of objects which are the
statistics which can be collected from a ds1
interface that is running transparent or unframed
lineType. Statistics not in this list should
return noSuchInstance."
::= { ds1Groups 7 }
ds1NearEndOptionalTrapGroup NOTIFICATION-GROUP
NOTIFICATIONS { dsx1LineStatusChange }
STATUS current
DESCRIPTION
"A collection of notifications that may be
implemented on DS1 and DS2 interfaces."
::= { ds1Groups 8 }
ds1ChanMappingGroup OBJECT-GROUP
OBJECTS { dsx1ChanMappedIfIndex }
STATUS current
DESCRIPTION
"A collection of objects that give an mapping of
DS3 Channel (ds1ChannelNumber) to ifIndex."
::= { ds1Groups 9 }
END
4. Appendix A - Use of dsx1IfIndex and dsx1LineIndex
This Appendix exists to document the previous use if dsx1IfIndex and
dsx1LineIndex and to clarify the relationship of dsx1LineIndex as
defined in rfc1406 with the dsx1LineIndex as defined in this
document.
The following shows the old and new definitions and the relationship:
[New Definition]: "This object should be made equal to ifIndex. The
next paragraph describes its previous usage. Making the object equal
to ifIndex allows proper use of ifStackTable and ds0/ds0bundle mibs.
[Old Definition]: "This object is the identifier of a DS1 Interface
on a managed device. If there is an ifEntry that is directly
associated with this and only this DS1 interface, it should have the
same value as ifIndex. Otherwise, number the dsx1LineIndices with an
unique identifier following the rules of choosing a number that is
greater than ifNumber and numbering the inside interfaces (e.g.,
equipment side) with even numbers and outside interfaces (e.g,
network side) with odd numbers."
When the "Old Definition" was created, it was described this way to
allow a manager to treat the value _as if_ it were and ifIndex, i.e.
the value would either be: 1) an ifIndex value or 2) a value that
was guaranteed to be different from all valid ifIndex values.
The new definition is a subset of that definition, i.e. the value is
always an ifIndex value.
The following is Section 3.1 from rfc1406:
Different physical configurations for the support of SNMP with DS1
equipment exist. To accommodate these scenarios, two different
indices for DS1 interfaces are introduced in this MIB. These indices
are dsx1IfIndex and dsx1LineIndex.
External interface scenario: the SNMP Agent represents all managed
DS1 lines as external interfaces (for example, an Agent residing on
the device supporting DS1 interfaces directly):
For this scenario, all interfaces are assigned an integer value equal
to ifIndex, and the following applies:
ifIndex=dsx1IfIndex=dsx1LineIndex for all interfaces.
The dsx1IfIndex column of the DS1 Configuration table relates each
DS1 interface to its corresponding interface (ifIndex) in the
Internet-standard MIB (MIB-II STD 17, RFC1213).
External&Internal interface scenario: the SNMP Agents resides on an
host external from the device supporting DS1 interfaces (e.g., a
router). The Agent represents both the host and the DS1 device. The
index dsx1LineIndex is used to not only represent the DS1 interfaces
external from the host/DS1-device combination, but also the DS1
interfaces connecting the host and the DS1 device. The index
dsx1IfIndex is always equal to ifIndex.
Example:
A shelf full of CSUs connected to a Router. An SNMP Agent residing on
the router proxies for itself and the CSU. The router has also an
Ethernet interface:
+-----+
| | |
| | | +---------------------+
|E | | 1.544 MBPS | Line#A | DS1 Link
|t | R |---------------+ - - - - - - - - - +------>
|h | | | |
|e | O | 1.544 MBPS | Line#B | DS1 Link
|r | |---------------+ - - - - - - - - - - +------>
|n | U | | CSU Shelf |
|e | | 1.544 MBPS | Line#C | DS1 Link
|t | T |---------------+ - - - -- -- - - - - +------>
| | | | |
|-----| E | 1.544 MBPS | Line#D | DS1 Link
| | |---------------+ - - - - -- - - - - +------>
| | R | |_____________________|
| | |
| +-----+
The assignment of the index values could for example be:
ifIndex (= dsx1IfIndex) dsx1LineIndex
1 NA NA (Ethernet)
2 Line#A Router Side 6
2 Line#A Network Side 7
3 Line#B Router Side 8
3 Line#B Network Side 9
4 Line#C Router Side 10
4 Line#C Network Side 11
5 Line#D Router Side 12
5 Line#D Network Side 13
For this example, ifNumber is equal to 5. Note the following
description of dsx1LineIndex: the dsx1LineIndex identifies a DS1
Interface on a managed device. If there is an ifEntry that is
directly associated with this and only this DS1 interface, it should
have the same value as ifIndex. Otherwise, number the
dsx1LineIndices with an unique identifier following the rules of
choosing a number greater than ifNumber and numbering inside
interfaces (e.g., equipment side) with even numbers and outside
interfaces (e.g., network side) with odd numbers.
If the CSU shelf is managed by itself by a local SNMP Agent, the
situation would be:
ifIndex (= dsx1IfIndex) dsx1LineIndex
1 Line#A Network Side 1
2 Line#A RouterSide 2
3 Line#B Network Side 3
4 Line#B RouterSide 4
5 Line#C Network Side 5
6 Line#C Router Side 6
7 Line#D Network Side 7
8 Line#D Router Side 8
5. Appendix B - The delay approach to Unavialable Seconds.
This procedure is illustrated below for a DS1 ESF interface. Similar
rules would apply for other DS1, DS2, and E1 interface variants. The
procedure guarantees that the statistical counters are correctly
updated at all times, although they lag real time by 10 seconds. At
the end of each 15 minutes interval the current interval counts are
transferred to the most recent interval entry and each interval is
shifted up by one position, with the oldest being discarded if
necessary in order to make room. The current interval counts then
start over from zero. Note, however, that the signal state
calculation does not start afresh at each interval boundary; rather,
signal state information is retained across interval boundaries.
+---------------------------------------------------------------------+
| READ COUNTERS & STATUS INFO FROM HARDWARE |
| |
| BPV EXZ LOS FE CRC CS AIS SEF OOF LOF RAI G1-G6 SE FE LV SL |
+---------------------------------------------------------------------+
| | | | | | | | | | | | | | | |
| | | | | | | | | | | | | | | |
V V V V V V V V V V V V V V V V
+---------------------------------------------------------------------+
| ACCUM ONE-SEC STATS, CHK ERR THRESHOLDS, & UPDT SIGNAL STATE |
| |
| |<---------- NEAR END ----------->| |<-------- FAR END ------>| |
| |
| LCV LES PCV ES CSS BES SES SEFS A/U PCV ES CSS BES SES SEFS A/U |
+---------------------------------------------------------------------+
| | | | | | | | | | | | | | | |
| | | | | | | | | | | | | | | |
V V V V V V V V | V V V V V V |
+------------------------------+ | +----------------------+ |
| ONE-SEC DELAY | | | ONE-SEC DELAY | |
| (1 OF 10) | | | (1 OF 10) | |
+------------------------------+ | +----------------------+ |
| | | | | | | | | | | | | | | |
/ / / / / / / / / / / / / / / /
| | | | | | | | | | | | | | | |
V V V V V V V V | V V V V V V |
+------------------------------+ | +----------------------+ |
| ONE-SEC DELAY | | | ONE-SEC DELAY | |
| (10 OF 10) | | | (10 OF 10) | |
+------------------------------+ | +----------------------+ |
| | | | | | | | | | | | | | | |
V V V V V V V V V V V V V V V V
+---------------------------------------------------------------------+
| UPDATE STATISTICS COUNTERS |
| |
|<-------------- NEAR END ----------->| |<--------- FAR END --------->|
| |
|LCV LES PCV ES CSS BES SES SEFS UAS DM PCV ES CSS BES SES SEFS UAS DM|
+---------------------------------------------------------------------+
Note that if such a procedure is adopted there is no current interval
data for the first ten seconds after a system comes up.
noSuchInstance must be returned if a management station attempts to
access the current interval counters during this time.
It is an implementation-specific matter whether an agent assumes that
the initial state of the interface is available or unavailable.
6. Intellectual Property
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementors or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
7. Acknowledgments
This document was produced by the Trunk MIB Working Group.
8. References
[1] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for
Describing SNMP Management Frameworks", RFC2271, January 1998.
[2] Rose, M. and K. McCloghrie, "Structure and Identification of
Management Information for TCP/IP-based Internets", STD 16, RFC
1155, May 1990.
[3] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
RFC1212, March 1991.
[4] Rose, M., "A Convention for Defining Traps for use with the
SNMP", RFC1215, March 1991.
[5] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Structure
of Management Information for Version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC1902, January 1996.
[6] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Textual
Conventions for Version 2 of the Simple Network Management
Protocol (SNMPv2)", RFC1903, January 1996.
[7] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Conformance Statements for Version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC1904, January 1996.
[8] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
Network Management Protocol", STD 15, RFC1157, May 1990.
[9] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Introduction to Community-based SNMPv2", RFC1901, January
1996.
[10] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport
Mappings for Version 2 of the Simple Network Management Protocol
(SNMPv2)", RFC1906, January 1996.
[11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
Processing and Dispatching for the Simple Network Management
Protocol (SNMP)", RFC2272, January 1998.
[12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
for version 3 of the Simple Network Management Protocol
(SNMPv3)", RFC2274, January 1998.
[13] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol
Operations for Version 2 of the Simple Network Management
Protocol (SNMPv2)", RFC1905, January 1996.
[14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
2273, January 1998.
[15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
Control Model (VACM) for the Simple Network Management Protocol
(SNMP)", RFC2275, January 1998.
[16] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB
using SMIv2", RFC2233, November 1997.
[17] AT&T Information Systems, AT&T ESF DS1 Channel Service Unit
User's Manual, 999-100-305, February 1988.
[18] AT&T Technical Reference, Requirements for Interfacing Digital
Terminal Equipment to Services Employing the Extended Superframe
Format, Publication 54016, May 1988.
[19] American National Standard for Telecommunications -- Carrier-to-
Customer Installation - DS1 Metallic Interface, T1.403, February
1989.
[20] CCITT Specifications Volume III, Recommendation G.703,
Physical/Electrical Characteristics of Hierarchical Digital
Interfaces, April 1991.
[21] ITU-T G.704: Synchronous frame structures used at 1544, 6312,
2048, 8488 and 44 736 kbit/s Hierarchical Levels, July 1995.
[22] American National Standard for Telecommunications -- Digital
Hierarchy -- Layer 1 In-Service Digital Transmission Performace
Monitoring, T1.231, Sept 1993.
[23] CCITT Specifications Volume IV, Recommendation O.162, Equipment
To Perform In Service Monitoring On 2048 kbit/s Signals, July
1988.
[24] CCITT Specifications Volume III, Recommendation G.821, Error
Performance Of An International Digital Connection Forming Part
Of An Integrated Services Digital Network, July 1988.
[25] AT&T Technical Reference, Technical Reference 62411, ACCUNET
T1.5 Service Description And Interface Specification, December
1990.
[26] CCITT Specifications Volume III, Recommendation G.706, Frame
Alignment and Cyclic Redundancy Check (CRC) Procedures Relating
to Basic Frame Structures Defined in Recommendation G.704, July
1988.
[27] CCITT Specifications Volume III, Recommendation G.732,
Characteristics Of Primary PCM Multiplex Equipment Operating at
2048 kbit/s, July 1988.
[28] Fowler, D., "Definitions of Managed Objects for the DS3/E3
Interface Types", RFC2496, Janaury 1999.
[29] Brown, T., and Tesink, K., "Definitions of Managed Objects for
the SONET/SDH Interface Type", Work in Progress.
[30] Fowler, D., "Definitions of Managed Objects for the Ds0 and
DS0Bundle Interface Types", RFC2494, January 1999.
[31] ITU-T G.775: Loss of signal (LOS) and alarm indication signal
(AIS) defect detection and clearance criteria, May 1995.
[32] ITU-T G.826: Error performance parameters and objectives for
international, constant bit rate digital paths at or above the
primary rate, November 1993.
[33] American National Standard for Telecommunications -- Digital
Hierarchy - Electrical Interfaces, T1.102, December 1993.
[34] American National Standard for Telecommunications -- Digital
Hierarchy - Format Specifications, T1.107, August 1988.
[35] Tesink, K., "Textual Conventions for MIB Modules Using
Performance History Based on 15 Minute Intervals", RFCXXXX,
January 1999.
9. Security Considerations
SNMPv1 by itself is such an insecure environment. Even if the
network itself is secure (for example by using IPSec), even then,
there is no control as to who on the secure network is allowed to
access and GET (read) the objects in this MIB.
It is recommended that the implementors consider the security
features as provided by the SNMPv3 framework. Specifically, the use
of the User-based Security Model RFC2274 [12] and the View-based
Access Control Model RFC2275 [15] is recommended.
It is then a customer/user responsibility to ensure that the SNMP
entity giving access to an instance of this MIB, is properly
configured to give access to those objects only to those principals
(users) that have legitimate rights to access them.
Setting any of the following objects to an inappropriate value can
cause loss of traffic. The definition of inappropriate varies for
each object. In the case of dsx1LineType, for example, both ends of
a ds1/e1 must have the same value in order for traffic to flow. In
the case of dsx1SendCode and dsx1LoopbackConfig, for another example,
traffic may stop transmitting when particular loopbacks are applied.
dsx1LineType
dsx1LineCoding
dsx1SendCode
dsx1LoopbackConfig
dsx1SignalMode
dsx1TransmitClockSource
dsx1Fdl
dsx1LineLength
dsx1Channelization
Setting the following object is mischevious, but not harmful to
traffic.
dsx1CircuitIdentifier
Setting the following object can cause an increase in the number of
traps received by the network management station.
dsx1LineStatusChangeTrabEnable
10. Author's Address
David Fowler
Newbridge Networks
600 March Road
Kanata, Ontario, Canada K2K 2E6
Phone: (613) 599-3600, ext 6559
EMail: davef@newbridge.com
11. Full Copyright Statement
Copyright (C) The Internet Society (1999). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
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