Subject: A few more atm1ng-03 nitpicks

From: Gary Hanson <[email-masked]>
Date: Thu, 9 Apr 1998 16:28:52 -0700 (PDT)

Kaj,

As long as you are working on atm1ng-03, I thought I might send
a few more items your way.

1.  No explicit statements exist to when or how the PVC or SVC
    cross-connect tables are to be used for Soft PVCs or SVCs.

    The DESCRIPTIONs for the atmVplConnKind and atmVclConnKind
    objects shed no light on this, nor does the AtmConnKind
    DESCRIPTION.  The latter DOES say that "an spvcInitiator is
    always cross-connected to an svcOutgoing, and an spvcTarget
    is always cross-connected to an svcIncoming", but it does
    NOT say how to make use of the PVC and SVC tables to actually
    accomplish this.  I am left unsure whether to use just the
    PVC table, just the SVC table, or both.  Also, no explicit
    statement is made about using the SVC cross-connect tables
    between svcIncoming and svcOutgoing virtual links.

    The DESCRIPTIONs for the atmVplCrossConnectIdentifier and
    atmVclCrossConnectIdentifier objects make NO mention at all
    of the possibility that their values identify entries in the
    atmSvcVpCrossConnectTable or the atmSvcVcCrossConnectTable,
    and yet specifically mention that their values ARE to be used
    to identify entries in the atmVpCrossConnectTable or the
    atmVcCrossConnectTable.

    This leaves the whole matter of how and when entries in these
    sets of tables are to be used COMPLETELY UNDEFINED between
    the ATM-MIB, the ATM2-MIB, and the ATM-TC-MIB, which I happen
    to think is a serious problem.  I had asked about this on the
    atommib WG list a while back, but have not heard any feedback.

    Since we have been assuming that it is legal to evolve the
    use of the atmV.lCrossConnectIdentifier objects to refer to
    either the PVC or SVC cross-connect tables, I think it is
    important to follow through and do the following:
    - fully describe the manner by which the atmV.lConnKind objects
      indicate to which tables the atmV.lCrossConnectIdentifier
      objects actually refer, and
    - supplement the atmV.lCrossConnectIdentifier DESCRIPTIONs to
      indicate the possibility that the index refers to different
      tables, depending upon the corresponding atmV.lConnKind
      value.

    Do you want proposed wording for this, or is it fairly obvious
    what needs to be done?

2.  The atmVplAdminStatus and atmVplLastChange objects were left
    out of the atmVplCrossConnectGroup and should be added.

3.  The atmVclAdminStatus and atmVclLastChange objects were left
    out of the atmVclCrossConnectGroup and should be added.

4.  The word "are" is missing between "that" and "cross-connected"
    in the DESCRIPTION for the GROUP atmVclCrossConnectGroup
    clause (on page 81).  (my gratuitous grammar nit-pick :-)

5.  Figure 3 is split at the boundary between pages 6 and 7, which
    makes it harder to read.  (my gratuitous layout nit-pick :-)

6.  The MIB boilerplate lists "four" major components, and then
    proceeds to list only three.  (True, there are four MIBs ath
    are described in three bullets, but why should the boilerplate
    be different between the ATM-MIB and ATM2-MIB documents?  Note
    that there has been discussion on the subject of MIB boilerplate
    issues on the snmpv3 WG list, and that these are not the ONLY
    documents that suffer (suffer?) from such inconsistencies.

    I believe that a universally applicable template for up-to-date
    MIB boilerplate should be made available to all MIB document
    editors; that the template should evolve as the standards and
    common practice evolve; that the MIB boilerplate should error
    on the side of inclusivenes rather than exclusiveness, when it
    comes to referencing older versions vs. newer versions of the
    documents, to satisfy the propelling of forward movement while
    still maintaining allowance for common practice; and that the
    RFC editor should be commisioned with the task of ensuring that
    no MIB document gets published without the latest and greatest
    set of MIB boilerplate comments.

I hope this information helps.  Thanks.

Regards,
Gary

---

From: Kaj Tesink <[email-masked]>
Date: Fri, 10 Apr 1998 16:30:06 -0400

Gary, thanks for tyhe detailed comments!
some annotations below.

kaj

>    Do you want proposed wording for this, or is it fairly obvious

Proposed wording to this list would be much appreciated to allow everyone to see;
i'm trying to edit the hopefully last version of this before Last Call.

>    out of the atmVplCrossConnectGroup and should be added.

i thought atmVplAdminStatus is not implemented for crossconnects?
atmVplLastChange seems indeed missing

>    out of the atmVclCrossConnectGroup and should be added.

as above

>I hope this information helps.  Thanks.

_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
_/                                                                      _/
_/  Kaj Tesink                                                          _/
_/  Bellcore                                                            _/
_/  Business Internet Professional Services  vmail (732) 758-5254       _/
_/  331 Newman Springs Rd.                   email [email-masked]  _/
_/  Red Bank, NJ 07701                     faxmail (732) 758-2269       _/
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_/  * NOTE AREA CODE CHANGE (908) --> (732) EFFECTIVE JUNE 1, 1997 *    _/
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_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/

---

From: Gary Hanson <[email-masked]>
Date: Thu, 16 Apr 1998 20:37:22 -0700 (PDT)

Kaj,

Here is my understanding of how the various cross-connect tables
are intended to be used (please correct me if I am wrong):
- For a PVC, the cross-connect between two VPLs is represented
  in the atmVpCrossConnectTable of the ATM-MIB, indexed by the
  atmVplCrossConnectIdentifier values for the two VPLs, and
  the cross-connect between two VCLs is represented in the
  atmVcCrossConnectTable of the ATM-MIB, indexed by the
  atmVclCrossConnectIdentifier values for the two VCLs.
- For an SVC or Soft PVC, the cross-connect between two VPLs is
  represented in the atmSvcVpCrossConnectTable of the ATM2-MIB,
  indexed by the atmVplCrossConnectIdentifier values for the two
  VPLs, and the cross-connect between two VCLs is represented in
  the atmSvcVcCrossConnectTable of the ATM2-MIB, indexed by the
  atmVclCrossConnectIdentifier values for the two VCLs.

I think these two bullets would be useful if added as two more
paragraphs at the end of section 6.5, which discusses the ATM
Virtual Link and Cross-Connect Groups.

Here are some object DESCRIPTION modifications that I think would
adequately clarify the use of the above rules for cross-connects
within the MIBs themselves:

- For AtmConnKind in ATM-TC-MIB, change:
                          "The use of call control. The use is as
                          follows:
                             pvc(1)
                                Virtual link of a PVC. Should not be
                                used in an PVC/SVC (i.e., SPVC)
                                crossconnect.
                             svcIncoming(2)
                                Virtual link established after a
                                received signaling request to setup
                                an SVC.
                             svcOutgoing(3)
                                Virtual link established after a
                                transmitted or forwarded signaling
                                request to setup an SVC.
                             spvcInitiator(4)
                                Virtual link at the PVC side of an
                                SVC/PVC crossconnect, where the
                                switch is the initiator of the SPVC
                                setup.
                             spvcTarget(5)
                                Virtual link at the PVC side of an
                                SVC/PVC crossconnect, where the
                                switch is the target of the SPVC
                                setup.

                          An spvcInitiator is always cross-connected to
                          an svcOutgoing, and an spvcTarget is always
                          cross-connected to an svcIncoming."
  to:
                          "The use of call control.  The use is as
                          follows:
                             pvc(1)
                                Virtual link of a PVC.  Should not be
                                used in a PVC/SVC (i.e., Soft PVC)
                                cross-connect.
                             svcIncoming(2)
                                Virtual link established after a
                                received signaling request to setup
                                an SVC.
                             svcOutgoing(3)
                                Virtual link established after a
                                transmitted or forwarded signaling
                                request to setup an SVC.
                             spvcInitiator(4)
                                Virtual link at the PVC side of an
                                SVC/PVC cross-connect, where the
                                switch is the initiator of the Soft
                                PVC setup.
                             spvcTarget(5)
                                Virtual link at the PVC side of an
                                SVC/PVC cross-connect, where the
                                switch is the target of the Soft PVC
                                setup.

                          For PVCs, a pvc is always cross-connected
                          to a pvc, and the cross-connect is always
                          represented in the atmVpCrossConnectTable
                          or the atmVcCrossConnectTable of the
                          ATM-MIB, depending upon whether the links
                          are VPLs or VCLs, respectively.

                          For SVCs, an svcIncoming is always
                          cross-connected to an svcOutgoing, and
                          the cross-connect is always represented in
                          the atmSvcVpCrossConnectTable or the
                          atmSvcVcCrossConnectTable of the ATM2-MIB,
                          depending upon whether the links are VPLs
                          or VCLs, respectively.

                          For Soft PVCs, an spvcInitiator is always
                          cross-connected to an svcOutgoing, and an
                          spvcTarget is always cross-connected to an
                          svcIncoming.  In either of these cases,
                          the cross-connect is always represented in
                          the atmSvcVpCrossConnectTable or the
                          atmSvcVcCrossConnectTable of the ATM2-MIB,
                          depending upon whether the links are VPLs
                          or VCLs, respectively."

  (Note also the change of "SPVC" to "Soft PVC", to follow the
  terminology used in the various ATM Forum specifications, as well
  as to help avoid too many acronyms floating around all with the
  letters "S", "P", "V", and "C" in various combinations.  It would
  be nice if this were changed in the ATM2-MIB as well....)

- For atmVplConnKind in ATM-MIB, change:
                     "The use of call control."
  to:
                     "The use of call control.  The value of pvc
                      indicates that any cross-connect involving this
                      VPL and other VPLs will be represented in the
                      atmVpCrossConnectTable of this MIB, indexed by
                      the value of atmVplCrossConnectIdentifier.  For
                      other atmVplConnKind values, any cross-connect
                      involving this VPL and other VPLs will be
                      represented in the atmSvcVpCrossConnectTable of
                      the ATM2-MIB, again indexed by the value of
                      atmVplCrossConnectIdentifier.  Note that
                      entries in the atmVpCrossConnectTable are
                      created by management action, whereas entries
                      in the atmSvcVpCrossConnectTable (as well as
                      the svcIncoming and svcOutgoing VPL entries
                      themselves) are created as a side-effect of
                      ATM signalling protocols.  At no time should
                      a given atmVplCrossConnectIdentifier value
                      index entries in both of these cross-connect
                      tables."

- For atmVclConnKind in ATM-MIB, change:
                     "The use of call control."
  to:
                     "The use of call control.  The value of pvc
                      indicates that any cross-connect involving this
                      VCL and other VCLs will be represented in the
                      atmVcCrossConnectTable of this MIB, indexed by
                      the value of atmVclCrossConnectIdentifier.  For
                      other atmVclConnKind values, any cross-connect
                      involving this VCL and other VCLs will be
                      represented in the atmSvcVcCrossConnectTable of
                      the ATM2-MIB, again indexed by the value of
                      atmVclCrossConnectIdentifier.  Note that
                      entries in the atmVcCrossConnectTable are
                      created by management action, whereas entries
                      in the atmSvcVcCrossConnectTable (as well as
                      the svcIncoming and svcOutgoing VCL entries
                      themselves) are created as a side-effect of
                      ATM signalling protocols.  At no time should
                      a given atmVclCrossConnectIdentifier value
                      index entries in both of these cross-connect
                      tables."

- For atmVplCrossConnectIdentifier in ATM-MIB, change:
                     "This object is implemented only for a VPL
                      which is cross-connected to other VPLs
                      that belong to the same VPC.  All such
                      associated VPLs have the same value of this
                      object, and all their cross-connections are
                      identified by entries in the
                      atmVpCrossConnectTable for which
                      atmVpCrossConnectIndex has the same value.
                      The value of this object is initialized by the
                      agent after the associated entries in the
                      atmVpCrossConnectTable have been created."
  to:
                     "This object is implemented only for a VPL
                      which is cross-connected to other VPLs
                      that belong to the same VPC.  All such
                      associated VPLs have the same value of this
                      object, and all their cross-connections are
                      identified either by entries that are indexed
                      by the same value of atmVpCrossConnectIndex in
                      the atmVpCrossConnectTable of this MIB or by
                      the same value of atmSvcVpCrossConnectIndex in
                      the atmSvcVpCrossConnectTable of the ATM2-MIB.
                      Which of these cross-connect tables is used
                      depends on the atmVplConnKind values of the
                      cross-connected VPLs.

                      The value of this object is initialized by the
                      agent after the associated entries in the
                      appropriate cross-connect table have been
                      created."

- For atmVclCrossConnectIdentifier in ATM-MIB, change:
                     "This object is implemented only for a VCL
                      which is cross-connected to other VCLs
                      that belong to the same VCC.  All such
                      associated VCLs have the same value of this
                      object, and all their cross-connections are
                      identified by entries in the
                      atmVcCrossConnectTable for which
                      atmVcCrossConnectIndex has the same value.
                      The value of this object is initialized by the
                      agent after the associated entries in the
                      atmVcCrossConnectTable have been created."
  to:
                     "This object is implemented only for a VCL
                      which is cross-connected to other VCLs
                      that belong to the same VCC.  All such
                      associated VCLs have the same value of this
                      object, and all their cross-connections are
                      identified either by entries that are indexed
                      by the same value of atmVcCrossConnectIndex in
                      the atmVcCrossConnectTable of this MIB or by
                      the same value of atmSvcVcCrossConnectIndex in
                      the atmSvcVcCrossConnectTable of the ATM2-MIB.
                      Which of these cross-connect tables is used
                      depends on the atmVclConnKind values of the
                      cross-connected VCLs.

                      The value of this object is initialized by the
                      agent after the associated entries in the
                      appropriate cross-connect table have been
                      created."

- For atmVpCrossConnectIndex in ATM-MIB, change:
                     "A unique value to identify this VP cross-connect."
  to:
                     "A unique value to identify this VP cross-connect.
                      For each VPL associated with this cross-connect,
                      the agent reports this cross-connect index value
                      in the atmVplCrossConnectIdentifier attribute of
                      the corresponding atmVplTable entries."

- For atmVcCrossConnectIndex in ATM-MIB, change:
                     "A unique value to identify this VC cross-connect."
  to:
                     "A unique value to identify this VC cross-connect.
                      For each VCL associated with this cross-connect,
                      the agent reports this cross-connect index value
                      in the atmVclCrossConnectIdentifier attribute of
                      the corresponding atmVclTable entries."

- For atmSvcVpCrossConnectIndex in ATM2-MIB, change:
                     "A unique value to identify this SVPC
                     cross-connect."

  to:
                     "A unique value to identify this SVPC
                     cross-connect.  For each VPL associated with
                     this cross-connect, the agent reports this
                     cross-connect index value in the
                     atmVplCrossConnectIdentifier attribute of
                     the corresponding atmVplTable entries in the
                     ATM-MIB."
                       
- For atmSvcVcCrossConnectIndex in ATM2-MIB, change:
                     "A unique value to identify this SVCC
                     cross-connect."
  to:
                     "A unique value to identify this SVCC
                     cross-connect.  For each VCL associated with
                     this cross-connect, the agent reports this
                     cross-connect index value in the
                     atmVclCrossConnectIdentifier attribute of
                     the corresponding atmVclTable entries in the
                     ATM-MIB."

I hope these DESCRIPTIONs don't seem too painfully wordy, but that
they instead help make it clearer how these objects cross-reference
each other between the various MIBs.

Regards,
Gary

> i thought atmVplAdminStatus is not implemented for crossconnects?

Oops....good point.  I forgot that.

> >    out of the atmVclCrossConnectGroup and should be added.

Ditto.

> [...]

---

From: Mickey Spiegel <[email-masked]>
Date: Thu, 16 Apr 1998 22:14:05 -0700

Gary and Kaj, 

I think these are good suggestions.

I see one place where I disagree with the proposed wording.  This

> - For AtmConnKind in ATM-TC-MIB, change:

<snip>

>                           svcIncoming.

I believe this to be overly restrictive.  A spvcInitiator
cross-connected to a spvcTarget should be valid.  A network using
only Soft PVCs should not have to figure out if the far end is on
the same switch or not.  It should be able to uniformly use Soft PVC
configuration.  I know of at least one large production network that
uses this functionality.

Mickey

---

From: Gary Hanson <[email-masked]>
Date: Fri, 17 Apr 1998 08:05:30 -0700 (PDT)

Mickey,

That's a good point.  I agree that spvcInitiator to spvcTarget
should also be allowed.  How about the following wording for
the relevant paragraph in the AtmConnKind TEXTUAL-CONVENTION:

                          For Soft PVCs, an spvcInitiator is either
                          cross-connected to an svcOutgoing or an
                          spvcTarget, and an spvcTarget is either
                          cross-connected to an svcIncoming or an
                          spvcInitiator.  In any of these cases,
                          the cross-connect is always represented in
                          the atmSvcVpCrossConnectTable or the
                          atmSvcVcCrossConnectTable of the ATM2-MIB,
                          depending upon whether the links are VPLs
                          or VCLs, respectively."

Gary

---

From: Mickey Spiegel <[email-masked]>
Date: Fri, 17 Apr 1998 10:23:07 -0700

Gary,

Looks good to me.

Mickey