RFC 2214
Integrated Services Management Information Base Guaranteed Service Extensions using SMIv2
RFC 2214: Integrated Services Management Information Base, Guaranteed Service Extensions using SMIv2 🎀
Authors: F. Baker (Cisco Systems), J. Krawczyk (ArrowPoint Communications), A. Sastry (Cisco Systems) 💅 Category: Standards Track 🌸 Date: September 1997 🦋 Obsoletes and updates: the title block doesn't list anything it obsoletes or updates. 🙈
Status of this Memo
okay so this one is an Internet standards track protocol for the Internet community, and it's basically asking for discussion and suggestions for improvements 🫶 If you want the current standardization state and status of this protocol, check the current edition of "Internet Official Protocol Standards" (STD 1). Distribution of this memo is unlimited ✨
Abstract
this memo defines a chunk of the Management Information Base (MIB) for network management protocols in TCP/IP-based internets 🧚 specifically, it defines objects for managing the interface attributes from the Guaranteed Service of the Integrated Services Model 💖 comments should go to the Integrated Services Working Group at intserv@isi.edu.
Table of Contents
1 The SNMPv2 Network Management Framework ............... 2
1.1 Object Definitions .................................. 2
2 Overview .............................................. 2
2.1 Textual Conventions ................................. 2
3 Definitions ........................................... 3
3.1 Interface Attributes Database ....................... 3
3.2 Notifications ....................................... 6
4 Security Considerations ............................... 7
5 Authors' Addresses .................................... 8
6 Acknowledgements ...................................... 8
7 References ............................................ 81. The SNMPv2 Network Management Framework ✨
the SNMPv2 Network Management Framework has four main pieces 🍓
- RFC 1441 defines the SMI, the mechanisms used for describing and naming objects for the purpose of management.
- STD 17, RFC 1213 defines MIB-II, the core set of managed objects for the Internet suite of protocols.
- RFC 1445 defines the administrative and other architectural aspects of the framework.
- RFC 1448 defines the protocol used for network access to managed objects.
the Framework also lets people define new objects for experimentation and evaluation 🔥
1.1. Object Definitions
managed objects are accessed through a virtual information store called the Management Information Base, or MIB 🌈 objects in the MIB are defined using the subset of Abstract Syntax Notation One (ASN.1) that the SMI defines 💜 each object type is named by an OBJECT IDENTIFIER, which is an administratively assigned name. the object type together with an object instance is what uniquely identifies one specific instance of the object 🦋 and because humans like nice names, we often use a textual string called the descriptor to refer to the object type 🫶
2. Overview ✨
2.1. Textual Conventions
this MIB document introduces several new data types as textual conventions 🎀 they make the specification easier to read and can make it easier to compare with other specifications when that's useful 💅 Here's the important bit: introducing these textual conventions has no effect on the syntax or the semantics of any managed objects. they're just an artifact of the explanation method 🙈 objects defined using them are always encoded using the rules that define the primitive type, so no changes to the SMI or the SNMP are needed to support them. they're only there for the convenience of readers and writers, in pursuit of the elusive goal of clear, concise, and unambiguous MIB documents 😭✨
3. Definitions 💜
here's the MIB module itself 🧚 it uses the extended OBJECT-TYPE macro described in [9].
INTEGRATED-SERVICES-GUARANTEED-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE FROM SNMPv2-SMI
RowStatus FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF
intSrv FROM INTEGRATED-SERVICES-MIB
ifIndex FROM IF-MIB;
-- This MIB module uses the extended OBJECT-TYPE macro as
-- defined in [9].
intSrvGuaranteed MODULE-IDENTITY
LAST-UPDATED "9511030500Z" -- Thu Aug 28 09:04:22 PDT 1997
ORGANIZATION "IETF Integrated Services Working Group"
CONTACT-INFO
" Fred Baker
Postal: Cisco Systems
519 Lado Drive
Santa Barbara, California 93111
Tel: +1 805 681 0115
E-Mail: fred@cisco.com"
DESCRIPTION
"The MIB module to describe the Guaranteed Service of
the Integrated Services Protocol"
::= { intSrv 5 }
intSrvGuaranteedObjects OBJECT IDENTIFIER
::= { intSrvGuaranteed 1 }
intSrvGuaranteedNotifications OBJECT IDENTIFIER
::= { intSrvGuaranteed 2 }
intSrvGuaranteedConformance OBJECT IDENTIFIER
::= { intSrvGuaranteed 3 }3.1. Interface Attributes Database 🦋
this is the part of the MIB that holds info shared with other reservation procedures, like ST-II 🌸
-- The Integrated Services Interface Attributes Database
-- contains information that is shared with other reservation
-- procedures such as ST-II.
intSrvGuaranteedIfTable OBJECT-TYPE
SYNTAX SEQUENCE OF IntSrvGuaranteedIfEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The attributes of the system's interfaces ex-
ported by the Guaranteed Service."
::= { intSrvGuaranteedObjects 1 }
intSrvGuaranteedIfEntry OBJECT-TYPE
SYNTAX IntSrvGuaranteedIfEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The reservable attributes of a given inter-
face."
INDEX { ifIndex }
::= { intSrvGuaranteedIfTable 1 }
IntSrvGuaranteedIfEntry ::=
SEQUENCE {
intSrvGuaranteedIfBacklog INTEGER,
intSrvGuaranteedIfDelay INTEGER,
intSrvGuaranteedIfSlack INTEGER,
intSrvGuaranteedIfStatus RowStatus
}the Backlog object is the data backlog that comes from how a specific implementation deviates from a strict bit-by-bit service 🧁 for example, with packetized weighted fair queueing, Backlog is set to the Maximum Packet Size 💅
intSrvGuaranteedIfBacklog OBJECT-TYPE
SYNTAX INTEGER (0..'0FFFFFFF'h)
UNITS "bytes"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The Backlog parameter is the data backlog
resulting from the vagaries of how a specific
implementation deviates from a strict bit-by-
bit service. So, for instance, for packetized
weighted fair queueing, Backlog is set to the
Maximum Packet Size.
The Backlog term is measured in units of bytes.
An individual element can advertise a Backlog
value between 1 and 2**28 (a little over 250
megabytes) and the total added over all ele-
ments can range as high as (2**32)-1. Should
the sum of the different elements delay exceed
(2**32)-1, the end-to-end error term should be
(2**32)-1."
::= { intSrvGuaranteedIfEntry 1 }the Delay object is the maximum packet transfer delay through a service element, no matter the bucket size 🌈 the example here is a simple router, where you'd add up the worst case time to get from the input interface to the processor and then from the processor to the outbound interface (assuming the queueing schemes work correctly) ⭐ for Ethernet, it might be the worst case delay when the maximum number of collisions happens 💀
intSrvGuaranteedIfDelay OBJECT-TYPE
SYNTAX INTEGER (0..'0FFFFFFF'h)
UNITS "microseconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The Delay parameter at each service element
should be set to the maximum packet transfer
delay (independent of bucket size) through the
service element. For instance, in a simple
router, one might compute the worst case amount
of time it make take for a datagram to get
through the input interface to the processor,
and how long it would take to get from the pro-
cessor to the outbound interface (assuming the
queueing schemes work correctly). For an Eth-
ernet, it might represent the worst case delay
if the maximum number of collisions is experi-
enced.
The Delay term is measured in units of one mi-
crosecond. An individual element can advertise
a delay value between 1 and 2**28 (somewhat
over two minutes) and the total delay added all
elements can range as high as (2**32)-1.
Should the sum of the different elements delay
exceed (2**32)-1, the end-to-end delay should
be (2**32)-1."
::= { intSrvGuaranteedIfEntry 2 }the Slack object is the big brain one 🧠✨ if a network element uses some slack, Si, to shrink the resources it reserved for flow i, then Si gets stored at that element. later, if reservation refreshes come in for flow i, the element must use that same Si without redoing any computation, which keeps the reservation process consistent 🫶
here's the example they give: say the required end-to-end delay, Dreq, is bigger than the maximum delay of the fluid flow system. Ctot is the sum of the Backlog terms end to end, and Dtot is the sum of the delay terms end to end. you get Dreq by setting R=r in the fluid delay formula:
b/r + Ctot/r + Dtot.and then the slack term is:
S = Dreq - (b/r + Ctot/r + Dtot).the slack can be used by network elements to adjust their local reservations so they can admit flows that would otherwise have been rejected 🔥 an element at an intermediate hop that can tell apart delay and rate guarantees can use this info to lower the resources allocated to the flow. for example, by taking some slack s <= S, an RCSD scheduler [5] can raise the local delay bound, d, for the flow to d+s. given an RSpec, (Rin, Sin), it does that by setting Rout = Rin and Sout = Sin - s 💖
a WFQ scheduler can do something similar: it lowers its local reservation from Rin to Rout by spending some of the slack in the RSpec. this works using the transformation rules from the previous section, which make sure the reduced reservation level won't increase the overall end-to-end delay 🌸
intSrvGuaranteedIfSlack OBJECT-TYPE
SYNTAX INTEGER (0..'0FFFFFFF'h)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"If a network element uses a certain amount of
slack, Si, to reduce the amount of resources
that it has reserved for a particular flow, i,
the value Si should be stored at the network
element. Subsequently, if reservation re-
freshes are received for flow i, the network
element must use the same slack Si without any
further computation. This guarantees consisten-
cy in the reservation process.
As an example for the use of the slack term,
consider the case where the required end-to-end
delay, Dreq, is larger than the maximum delay
of the fluid flow system. In this, Ctot is the
sum of the Backlog terms end to end, and Dtot
is the sum of the delay terms end to end. Dreq
is obtained by setting R=r in the fluid delay
formula, and is given by
b/r + Ctot/r + Dtot.
In this case the slack term is
S = Dreq - (b/r + Ctot/r + Dtot).
The slack term may be used by the network ele-
ments to adjust their local reservations, so
that they can admit flows that would otherwise
have been rejected. A service element at an in-
termediate network element that can internally
differentiate between delay and rate guarantees
can now take advantage of this information to
lower the amount of resources allocated to this
flow. For example, by taking an amount of slack
s <= S, an RCSD scheduler [5] can increase the
local delay bound, d, assigned to the flow, to
d+s. Given an RSpec, (Rin, Sin), it would do so
by setting Rout = Rin and Sout = Sin - s.
Similarly, a network element using a WFQ
scheduler can decrease its local reservation
from Rin to Rout by using some of the slack in
the RSpec. This can be accomplished by using
the transformation rules given in the previous
section, that ensure that the reduced reserva-
tion level will not increase the overall end-
to-end delay."
::= { intSrvGuaranteedIfEntry 3 }the Status object is the RowStatus for interfaces configured for Guaranteed Service 💜
intSrvGuaranteedIfStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"'valid' on interfaces that are configured for
the Guaranteed Service."
::= { intSrvGuaranteedIfEntry 4 }3.2. Notifications 🔔
-- No notifications are currently defined-- conformance information
intSrvGuaranteedGroups OBJECT IDENTIFIER
::= { intSrvGuaranteedConformance 1 }
intSrvGuaranteedCompliances OBJECT IDENTIFIER
::= { intSrvGuaranteedConformance 2 }
-- compliance statements
intSrvGuaranteedCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement "
MODULE -- this module
MANDATORY-GROUPS {
intSrvGuaranteedIfAttribGroup
}
::= { intSrvGuaranteedCompliances 1 }
intSrvGuaranteedIfAttribGroup OBJECT-GROUP
OBJECTS {
intSrvGuaranteedIfBacklog,
intSrvGuaranteedIfDelay,
intSrvGuaranteedIfSlack,
intSrvGuaranteedIfStatus
}
STATUS current
DESCRIPTION
"These objects are required for Systems sup-
porting the Guaranteed Service of the Integrat-
ed Services Architecture."
::= { intSrvGuaranteedGroups 2 }
END4. Security Considerations ✨
okay so, bestie, this one is short and sweet 🫶 Setting stuff up with an SNMP SET gives you an RSVP or Integrated Services reservation, but it follows different rules than when the reservation gets negotiated through RSVP itself. 👀 That's the main thing to clock here.
Besides that, there are no other security considerations. The only ones that apply are the ones SNMP already comes with 🔐 So if you're worried about security, go look at SNMP's own protections, because nothing extra is being added here. 💅
5. Authors' Addresses 🎀
Here are the people who wrote it, with their addresses and contact details 💌
Fred Baker
Postal: Cisco Systems
519 Lado Drive
Santa Barbara, California 93111
Phone: +1 805 681 0115
EMail: fred@cisco.com
John Krawczyk
Postal: ArrowPoint Communications
235 Littleton Road
Westford, Massachusetts 01886
Phone: +1 508 692 5875
EMail: jjk@tiac.net
Arun Sastry
Postal: Cisco Systems
210 W. Tasman Drive
San Jose, California 95314
Phone: +1 408 526 7685
EMail: arun@cisco.com6. Acknowledgements 🙌
This document came out of the Integrated Services Working Group. Big group effort, literally iconic 👑
7. References 📚
- [1] Rose, M., Editor, "Management Information Base for Network Management of TCP/IP-based internets", STD 17, RFC 1213, May 1990.
- [2] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization. International Standard 8824, (December, 1987).
- [3] Information processing systems - Open Systems Interconnection - Specification of Basic Encoding Rules for Abstract Notation One (ASN.1), International Organization for Standardization. International Standard 8825, (December, 1987).
📦 where this page comes from
- ietf: rfc2214 1997-09
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms