Internet Draft
GSMP Working Group                                 Avri Doria, Nokia
Internet-Draft                            Fiffi Hellstrand, Ericsson
Expiration Date: Dec 1999                     Constantin Adam, Xbind
                                                       23 June, 1999

    Support Structure for Optional Abstract or Resource Models
                  <draft-doria-gsmp-option-arm-00.txt>


Status of this Memo

     This document is an Internet-Draft and is in full conformance with
     all provisions of Section 10 of RFC2026.

     Internet-Drafts are working documents of the Internet Engineering
     Task Force (IETF), its areas, and its working groups.  Note that
     other groups may also distribute working documents as Internet-
     Drafts.

     Internet-Drafts are draft documents valid for a maximum of six
     months and may be updated, replaced, or obsoleted by other
     documents at any time.  It is inappropriate to use Internet-
     Drafts as reference material or to cite them other than as "work
     in progress."

     The list of current Internet-Drafts can be accessed at:
     http://www.ietf.org/ietf/1id-abstracts.txt

     The list of Internet-Draft Shadow Directories can be accessed at:
     http://www.ietf.org/shadow.html.

     Distribution of this memo is unlimited.

     Copyright Notice

     Copyright (C) The Internet Society (1999).  All Rights Reserved.


Abstract

A set of modifications to the GSMP protocol is proposed in order to
allow the GSMP to support optional abstract resource models for Quality
of Service.






INTERNET-DRAFT...Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 2]

1.     Overview

The GSMP V3[3] rework of the GSMP V2[2] specification chapter 9, Quality
of Service Message, with a default service model based on draft-worster-
gsmp-qos-00[4]. Chapter 9 had contained an experimental abstract
resource model for Quality of Service.

In addition to supporting a default Service Model,  a mechanism is still
required to support optional Abstract/Resource Models (ARM). This
proposal recommends such a structure.  The proposed changes include a
change to the Configuration Request messages as well as a redefinition
of the QoS Model Selector and the Service Selector fields in connection
messages.

The proposal also recommends reserving a group of message numbers for
use by Abstract/Resource Model definitions.

This proposal only includes the changes that need to be made to the GSMP
specification to support the ARM framework.  Optional models would be
defined in separate documents.  An ARM specification is required to
define the messages and the fields necessary for implementing the model.
ARM Types also need to be allocated and registered.


2.     Changes to Configuration Message processing

Currently the switch configuration exchange is rather simple.  The
controller requests the switch configuration, and the switch responds
with its firmware version, maximum number of outstanding messages,
switch type and switch identification.  This proposal recommends adding
a QoS model type (MType) exchange to this interchange.

After adjacency between a controller and a switch is first established
the controller that opts to use a  model type other then the default
would send the switch configuration request including the requested
model type in the request message.  It would need to do this before any
connection messages were exchanged.  If the switch could support the
request model type then the switch would respond by sending back the
requested model type as an indication that it was able to support the
request. If the switch cannot support the requested model type,  it
would send back the default MType; that is MType=0.  Switch
configuration response messages from the switch would also include a
list of up to 3 available model types that the controller could choose
between.

The exchange may continue until the controller sends a requested MType
which the switch can support. If the exchange stopped without



INTERNET-DRAFT   Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 3]

confirmation of an alternate switch model, then the default model would
be used.

Once a model type has been established for the switch, it cannot be
changed without full restart; that it the re-establishment of adjacency
with the resetting of all connections.  Additionally the model can only
be set until the first connection message is sent.

2.1  Changes to the system configuration request message (# 64)

Currently all configuration request messages have the following form:


   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Version    | Message Type  |    Result     |     Code      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Transaction Identifier                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Port                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

However, the Switch Configuration request does not use the Port field
for obvious reasons.  The system configuration request message would be
changed to:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Version    | Message Type  |    Result     |     Code      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Transaction Identifier                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   MType       |                    x                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


Where MType represents a requested model type:

    0            ¡  Indicates use of the default GSMP model
    1            ¡  Indicates use IEEE qGSMP Model[6]
    2            -  Indicates use of Sprint Framework[5]
    3 - 200      -  Reserved
    201 - 255    -  Experimental






INTERNET-DRAFT   Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 4]


2.2  Switch Configuration Response Message (#64)

The switch configuration response message currently has the following
form:


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Version    | Message Type  |    Result     |     Code      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Transaction Identifier                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Firmware Version Number    |          Window Size          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Switch Type          |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
   |                          Switch Name                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   It will be changed as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Version    | Message Type  |    Result     |     Code      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Transaction Identifier                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Firmware Version Number    |          Window Size          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Switch Type          |                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
   |                          Switch Name                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     MType     |     MType     |     MType     |     MType     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


MType: represents a ARM type:

    0            ¡  Indicates use of the default GSMP model
    1            ¡  Indicates use IEEE qGSMP Model[6]
    2            -  Indicates use of Sprint Framework[5]
    3 - 200      -  Reserved
    201 - 255    -  Experimental



INTERNET-DRAFT   Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 5]

The first MType in the list of MTypes is either the MTypes as proposed
in the request if accepted by the switch or the default MType.  The rest
of the MTypes in the list are MTypes the switch can offer or 0 pads.


3.       Proposed Connection Management message changes

The following changes apply to the connection management messages; 16,
22, 26, and 27.

3.1  General Message definitions

In order to make the service selector as useful as possible, it will be
extended to 4 octets from the current 2 octets. That is, in request
messages, the Number of Branches field will be removed and the Service
Selector will extend for the entire 32 bits. In response messages, the
Service Selector field will be removed, replaced by the Number of
Branches field and a reserved field.

3.1.1 Connection Management Request Message

       0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Version    | Message Type  |    Result     |     Code      |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                    Transaction Identifier                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      Port Session Number                      |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          Input Port                           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |M|B|T|R|                                                       |
       +-+-+-+-+                  Input Label                          ~
       ~                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          Output Port                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |QMS|T|R|                                                       |
       +-+-+-+-+                  Output Label                         ~
       ~                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Service Selector                        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+






INTERNET-DRAFT   Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 6]

3.1.2 Connection Management Response Message

   0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Version    | Message Type  |    Result     |     Code      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Transaction Identifier                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Port Session Number                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          Input Port                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |M|B|T|R|                                                       |
   +-+-+-+-+                  Input Label                          ~
   ~                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          Output Port                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |QMS|T|R|                                                       |
   +-+-+-+-+                  Output Label                         ~
   ~                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Number of Branches       |            Reserved           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


3.2  Changes to Connection Message Fields

3.2.1 QoS Model Selector

QoS Model Selector will be modified as follows in connection management
message:

      QMS: QoS Model Selector


      The QoS Model Selector is used to specify a QoS Model for
      connection. The value of QMS indicates the value in the Service
      Selector should be interpreted as a priority, a QoS profile or a
      service specification as shown:

       QMS QoS Model                     Service Selector
       --- ---------                     ----------------
       00 Simple Abstract                Model Priority
       01 QoS Profile Model              QoS Profile



INTERNET-DRAFT   Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 7]

       10 Service Model               Service Specification
       11 Optional ARM                ARM Specification

3.2.2 Service Selector

Service Selector field description in the connection management messages
will be modified as follows:

      This field can contain either a QoS Profile Identifier, a
      Priority, a Service Specification or an optional ARM indicator. If
      the QoS Model Selector is set to 0b00, the Service Selector field
      contains a Priority. If the QoS Model Selector is set to 0b01, the
      Service Selector field contains a QoS Profile. If the QoS Model
      Selector is set to 0b10, the Service Selector field contains a
      Service Specification.  If the QoS Model Selector is set to 0b11,
      the Service Selector field will contain a service indicator which
      has its meaning defined by the optional ARM being used as
      indicated in the MType field of the configuration message. The
      Service Selector field is only used in the Add Branch and Move
      Branch messages.

      When using the default service model, Priority specifies the
      priority of the connection for Add Branch and Move Branch messages
      that choose not to use a QoS profile, or a service specification.
      The highest priority is numbered zero and the lowest priority is
      numbered "Q-1" where "Q" is the number of priorities that the
      output port can support. The ability to offer different qualities
      of service to different connections based upon their priority is
      assumed to be a property of the output port of the switch. It is
      assumed that for virtual path connections or virtual channel
      connections that share the same output port, a cell or frame on a
      connection with a higher priority is much more likely to exit the
      switch before a cell or frame on a connection with a lower
      priority, if they are both in the switch at the same time. The
      number of priorities that each output port can support is given in
      the Port Configuration message. In order to maintain backward
      compatibility with earlier versions of the protocol, the Priority
      octets will occupy the 2 rightmost octets of the service selector.

      When using the default service model, a QoS Profile Identifier is
      an opaque 16-bit value. It is used to identify a QoS profile in
      the switch which specifies the Quality of Service required by the
      connection. QoS profiles are established by a mechanism external
      to GSMP.

      When using the default service model, a Service Specification is
      an alternative method of communicating the QoS requirements of a




INTERNET-DRAFT   Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 8]

         connection. The Service Specification is defined in GSMP V3[3]
         Chapter 9.

         When using an optional ARM, The meaning of Service selector is
         dependant on the definitions which are provided in the ARM
         specification.

4.       Message numbers reserved for Abstract Resource Models

Message sequence 200-249 are reserved for abstract resource model
message definition. These messages will be interpreted according to
definitions provided by the model description.  It is expected that ARM
specifications will include definitions of Model configuration,
connection management and status gathering messages in this group.


Author's Contact

       Avri Doria
       Nokia Telecommunications
       3 Burlington Woods Drive, Suite 250
       Burlington, MA 01803
       Phone: +1 781 359 5131
       Mobile: +1 617 678 9402
       avri.doria@ntc.nokia.com

       Fiffi Hellstrand
       Ericsson Telecom
       S-126 35 Stockholm
       Phone +46 8 719 4933
       Mobile +46 70 519 4933
       etxfiff@etxb.ericsson.se

       Constantin Adam
       Xbind, Inc.
       55 Broad Street, Suite 13C
       New York, NY 10004
       Phone: +1 212 809 3303
       Mobile +1 917 335 8161
       ctin@xbind.com

       Comments on this document should be sent to the authors or to the
       working group mailing list at gsmp@psyton.com.






INTERNET-DRAFT   Support structure for QoS Models         23.06.99



Doria                    Expires Dec 1999                 [Page 9]



References

[1]  Newman, P, Edwards, W., Hinden, R., Hoffman, E. Ching Liaw, F.,
     Lyon, T. and Minshall, G., "Ipsilon's General Switch Management
     Protocol Specification," Version 1.1, RFC 1987, August 1996.

[2]  Newman, P, Edwards, W., Hinden, R., Hoffman, E., Ching Liaw, F.,
     Lyon, T. and Minshall, G., "Ipsilon's General Switch Management
     Protocol Specification," Version 2.0, RFC 2397, March 1998.

[3]  GSMP Working Group, Tom Worster Editor, "General Switch
     Management Protocol V3", draft-ietf-gsmp-00.txt, June, 1999

[4]  GSMP Working Group, Worster, T; Hellstrand, F; Doria, A; "A QoS
     Model for GSMP", draft-worster-gsmp-qos-00.txt, Feb, 1999

[5]  GSMP Working Group, Ranganathan, P; Sreenivasamurthy, D; Evans,
     J; Kaushal, A; "A framework for QoS support for open control",
     draft-ranganathan-gsmp-qos-framework-00.txt, Dec 1998

[6]  IEEE/WG 1520, Adam, C; Lazar, A; Nanadikesan, M; "Proposal for
     Standaridizing the qGSMP protocol", P1520/TS/ATM-002,
     http://comet.columbia.edu/pin-atm/docs/P1520-TS-ATM-002R1.pdf,
     19 Jan, 1999




This document expires on 23 December 1999.

















INTERNET-DRAFT   Support structure for QoS Models         23.06.99