Subject: [MIB-DOCTORS] MIB Doctor review: http://www.ietf.org/internet-drafts/draft-ietf-ipcdn-pktc-signaling-13.txt

From: "Wijnen, Bert \(Bert\)" <[email-masked]>
Date: Tue, 5 Jun 2007 17:58:56 +0200

[bcc: to MIB doctors list]

Let me start to tell you that I am not a voice expert, so a lot of
the actual content of this MIB module is abacadabra for me. I am
assuming that other IPCDN WG members have evaluated (or will
evaluate) the actual content w.r.t. the technical details and
correctness.

Let me also say that I find this MIB module pretty wieldy,

Nevertheless, here are my MIB Doctor review comments.

More or less serious issues/concerns:

- writable objects MUST specify (for example in their DESCRIPTION 
  clause) the expected persistence behavior.

- I see various objects aka:
   pktcSigDevR0Cadence     OBJECT-TYPE
       SYNTAX      PktcRingCadence
       MAX-ACCESS  read-write
       STATUS      current
       DESCRIPTION
           " This object specifies ring cadence 0 (a user defined
             field). This object is required for the L line package."
       ::= { pktcSigDevObjects 5 }

  The fact that an object is required" is normally expressed in the
  MODULE-COMPLIANCE. The above object (together with several others) 
  seems conditionaly optional, which means you would group all such
  objects required for L line package in one OBJECT-GROUP and make
  that OBJECT-GROUP conditionaly mandatory.

- I wonder if the SYNTAX of SnmpAdminString makes sense for the
  objects pktcSigCapabilityVersion and pktcSigCapabilityVendorExt.
  It will work. But, SnmpAdminString is intended to contain human
  readable (in any language/character set) strings. It seems that the
  values that you allow are very restricted and certainly cannot
  be in any other language/character-set.
  I personally can live with it... but you might want to
  think of just an OCTET-STRING that you define exactly what it can
  contain.

- I find this strange:
  pktcSigPowerRingFrequency    OBJECT-TYPE
      SYNTAX       INTEGER {
                   f20Hz(1),
                   f25Hz(2),
                   f33Point33Hz(3),
                   f50Hz(4),
                   f15Hz(5),
                   f16Hz(6),
                   f22Hz(7),
                   f23Hz(8),
                   f45Hz(9)
      }
      UNITS "Hertz"

  Because tha value of the object is certainly not in "Hertz" units.
  A value of 1 doe not represent 1 UNIT of "Hertz", but it represents
  20 Hertz. and so on... I think I would remove the UNITS clause.

  Same for pktcSigPulseSignalFrequency

- pktcSigPulseSignalTable DESCRIPTION clause speaks about the mandatory
  nature of this table for E line package. This is MODULE-COMPLIANCE
  stuff and should be expressed in the OBJECT-GROUP grouping and
  MODULE-COMPLIANCE.

  similar comment for pktcSigDevRingCadenceTable

- I see:
  pktcSigPulseSignalDbLevel    OBJECT-TYPE
      SYNTAX       TenthdBm (-350..0)
      UNITS        "dBm"

  I thought that the units were "1/10 of a dBm" ??

  same for pktcSigDevToneDbLevel

- Given the DESCRIPTION clause for
   pktcSigPulseSignalRepeatCount    OBJECT-TYPE
       SYNTAX       Unsigned32
  You might consider to make the syntax
       SYNTAX       Unsigned32 (1..50)

- This DESCRIPTION clause has to be incorrect:

   pktcSigDevRingCadenceEntry    OBJECT-TYPE
       SYNTAX       PktcSigDevRingCadenceEntry
       MAX-ACCESS   not-accessible
       STATUS       current
       DESCRIPTION
           " Unique value ranging from 0 to 127 that will correspond to
             the different ring cadences that are being supported by
             the device."

  After all, it is an "entry" or "row" definition and so it does not
have a
  value from 0-127. The INDEX object does.
  The DESCRIPTION clause of the INDEX object seems to be describing what
an 
  Entry is all about.

- What sort of duration (UNITS?) must I assume for:
      pktcSigDevToneFreqOnDuration OBJECT-TYPE
          SYNTAX       Unsigned32(0..5000)

  same question for pktcSigDevToneFreqOffDuration,

- Have seen a SYNTAX of
          SYNTAX       INTEGER {
                               fsk(1),
                               dtmf(2)
          }
  for the signaling protocol multiple times. 
  Candidate for a TEXTUAL-CONVENTION?

- For pktcNcsEndPntConfigPartialDialTO, what does a zero value mean?

  similar question for the other pktcNcs....TO objects

- I find it strange to see pktcNcsEndPntConfigStatus in the middle of
the
  table. But... it is not an error.

- For the read-create table, I wonder where the read-only objects
  pktcNcsEndPntStatusCallIpAddressType and
pktcNcsEndPntStatusCallIpAddress
  come from? How does the agent determine those addresses.?

- For pktcNcsGroup the DESCRIPTION clause talks about this group being
  mandatory for... That does NOT belong here. The fact if a group is
  mandatory or not is specified in the MODULE-COMPLIANCE statement.

Admin/Naming questions:

- The title speaks about:

      Network-Based Call Signaling (NCS) MIB for PacketCable and

  while the MIB Module is named: PKTC-IETF-SIG-MIB and pktcIetfSigMib
  Not that that is a bug... but it feels somewhat strange.

  Later in the document, at various places the "NCS MIB" term comes
back,
  and so people might expect to see IETF-NCS-MIB or ietfNcsMib as names?

- Section 4 states:

   Terminal Adapter (MTA) devices. The IETF NCS MIB module (PKTC-IETF-
   SIG-MIB) is intended to supersede various Signaling MIB modules from
   which it is partly derived:
     - the PacketCable 1.0 Signaling MIB Specification
       [PKT-SP-MIB-SIG-1.0],
     - the PacketCable 1.5 Signaling MIB Specification
       [PKT-SP-MIB-SIG-1.5],
     - the ITU-T IPCablecom Signaling MIB requirements [ITU-T-J169],
     - the ETSI Signaling MIB [ETSI-TS-101-909-9]. The ETSI Signaling
       MIB requirements also refer to various signal characteristics
       defined in [ETSI-TS-101-909-4], [ETSI-EN-300-001],
       [ETSI-EN-300-659-1], [ETSI-EN-300-324-1] and [ETSI-TR-101-183].

  I know that many IPCDN WG members are all participating in
PackagetCable,
  so I assume that superseding (is that same as obsoleting in IETF
terms?)
  PacketCable documents is fine. But how about ITU-T and ETSI? Are they
  OK with the above statements?

- In section 4.1 I would use "MIB module" instead of "MIB"

- The groups listed in section 4.1 are not the same as the groups
  defined with the OBJECT-GROUP macros.

- Sect 4.3 states:
    pktcSigCompliances - this table has one object that has compliance
    statements for devices that implement Signaling on the MTA.

    pktcSigGroups - this table contains group of objects for the common
    portion of the PacketCable NCS and Signaling MIB.

    pktcInternationalGroup - this table extends this MIB Module by
    establishing a set of objects designed to support operations over
    the widest possible range of markets.

  while none of these 3 are "tables" in MIB speak.

- IN de MODULE-IDENTITY DESCRIPTION clause it states:

           Copyright (C) The Internet Society (2007). This version of
           this MIB module is part of RFC yyyy; see the RFC itself for
           full legal notices."

   That should be the new IETF Trust Copyright statement:

           Copyright (C) The IETF Trust (2007).  This version of this
           MIB module is part of RFC yyyy; see the RFC itself for full
           legal notices."  

- pktcNcsEndPntConfigTable and the objects in that table have a prefix
of
  pktcNcs.... Why not pktcSigNcs....  ???
  Just to better avoid any future name clashes in other MIB modules .

Nits:

- I see:
   pktcSigDevEchoCancellation  OBJECT-TYPE
       SYNTAX       TruthValue
       MAX-ACCESS   read-only
       STATUS       current
       DESCRIPTION
           " This object specifies if the device is capable of echo
             cancellation."
       ::= { pktcSigDevObjects 2 }

  And so I assume that the value true(1) means that the device is
  capable of echo cancellation. I think it would be clearer if that
  were explicitly stated.

  There are more of such objects of SYNTAX TruthValue that could
  be clarified in a similar way.

- there are some strange control characters in the document.
  Specifically in the section titles, for example:

    9. ^M  IANA Considerations

- Security Considerations:

   Even if the network itself is secure (for example by using IPSec),

  pls change IPSec into IPsec which is the proper spelling and part of
the
  latest security template.

---------------------------

references issues (found by my own tool):

!! Missing citation for Informative reference:
  P072 L048:    [ITU-T-E.180] ITU-T E.180: "Various Tones Used in
National Networks,

---------------------------

IDnits tells me:

     (See RFC 3967 for information about using normative references to
     lower-maturity documents in RFCs)
  -- Possible downref: Non-RFC (?) normative reference: ref.
'ITU-T-J169'

  -- Possible downref: Non-RFC (?) normative reference: ref.
'PKT-SP-CODEC'

  -- Possible downref: Non-RFC (?) normative reference: ref.
'PKT-SP-MGCP'

  -- Possible downref: Non-RFC (?) normative reference: ref.
'PKT-SP-PROV'

probably OK, just listing it for completeness.

Bert Wijnen  

> -----Original Message-----
> From: Romascanu, Dan (Dan) [mailto:[email-masked]] 
> Sent: Wednesday, May 16, 2007 12:17 PM
> To: MIB Doctors (E-mail)
> Cc: Jean-Francois Mule; Woundy,Richard
> Subject: [MIB-DOCTORS] Call for volunteer 
>
http://www.ietf.org/internet-drafts/draft-ietf-ipcdn-pktc-signaling-13.t
xt
> 
> 
> MIB Doctors,
> 
> We need a volunteer to review
>
http://www.ietf.org/internet-drafts/draft-ietf-ipcdn-pktc-signaling-13.t
xt. 
>  
> Please let me know if you have some available time for this 
> review during the next few weeks. 
> 
> Thanks and Regards,
> 
> Dan

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