Supporting J1 iftype in RFC 3895

["Orly Nicklass" <orly_n@rad.com>]

In order to accommodate clear support of J1 in the DS1 standard MIB
(RFC3895) according to the Japanese STD
JT-G704, JT-G706 and JT I.431-a, I propose to produce an ID as 3895bis
with  the following changes :

There are  2 significant  differences between J1 and T1:
1. CRC-6 calculation:  
2. Yellow alarm (RAI):   

 Item 2 is relevant only for D4 framing .

To support both issues we can add additional line type values :
dsx1J1ESF(14), 
 
dsx1J1D4(15), and
 
dsx1J1Unframed(16)   as shown below. (16) is just to note that we handle
J1 and not T1:

dsx1LineType OBJECT-TYPE
     SYNTAX  INTEGER {
                other(1),
                dsx1ESF(2),
                dsx1D4(3),
                dsx1E1(4),
                dsx1E1CRC(5),
                dsx1E1MF(6),
                dsx1E1CRCMF(7),
                dsx1Unframed(8),
                dsx1E1Unframed(9),
                dsx1DS2M12(10),
                dsx1E2(11),
                dsx1E1Q50(12),
                dsx1E1Q50CRC(13),
                dsx1J1ESF(14),                                  < --
-------------
                dsx1J1D4(15),                                     < --
-------------
                dsx1J1Unframed(16)                            < --
-------------
            }
     MAX-ACCESS  read-write
     STATUS  current
     DESCRIPTION
            "This variable indicates  the  variety  of  DS1
            Line  implementing  this  circuit.  The type of
            circuit affects the number of bits  per  second
            that  the circuit can reasonably carry, as well
            as the interpretation of the  usage  and  error
            statistics. The values, in sequence, describe:

                  TITLE:         SPECIFICATION:
                  dsx1ESF        Extended SuperFrame DS1
                                       (T1.107)
                  dsx1D4         AT&T D4 format DS1 (T1.107)
                  dsx1E1         ITU-T Recommendation G.704
                                       (Table 4a)
                  dsx1E1-CRC     ITU-T Recommendation G.704
                                       (Table 4b)
                  dsxE1-MF       G.704 (Table 4a) with TS16
                                        multiframing enabled
                  dsx1E1-CRC-MF  G.704 (Table 4b) with TS16
                                        multiframing enabled
                  dsx1Unframed   DS1 with No Framing
                  dsx1E1Unframed E1 with No Framing (G.703)
                  dsx1DS2M12     DS2 frame format (T1.107)
                  dsx1E2            E2 frame format (G.704)
                  dsx1E1Q50      TS16 bits 5,7,8 set to 101, [in
                                         all other cases it is set
                                         to 111.](ITU-T G.704,table 14)
                  dsx1E1Q50CRC   E1Q50 with CRC
                  dsx1J1ESF       J1 according to (JT-G704 and JT-G706
and JT-I431.).                         <---------------------
                  dsx1J1D4         J1 according to (JT-G704 and JT-G706
and JT-I431.).                         <---------------------
                  dsx1J1Unframed    J1 with No Framing
<---------------------

            For clarification, the capacity for each E1 type
            is as listed below:
            dsx1E1Unframed - E1, no framing = 32 x 64k = 2048k
            dsx1E1 or dsx1E1CRC - E1, with framing,
               no signalling = 31 x 64k = 1984k
            dsx1E1MF or dsx1E1CRCMF - E1, with framing,
               signalling = 30 x 64k = 1920k"
    REFERENCE
            "American National Standard for telecommunications -
               digital hierarchy - formats specification,
               ANSI-T1.107 - 1988.
            CCITT Specifications Volume III, Recommendation
               G.703, Physical/Electrical Characteristics
               of Hierarchical Digital Interfaces, April 1991.
            ITU-T-G.704: Synchronous frame structures used at
               1544, 6312, 2048, 8488 and 44 736 kbit/s
               Hierarchical Levels, July 1998.
<-----------------------
            JT-G.704: Synchronous frame structures used at
<------------------------
               Primary and Secondary Hierarchical Levels.
            JT-G706. Frame Alignment and Cyclic Redundancy 
               Check (CRC) Procedures.
           JT-I431. ISDN Primary Rate User-Network Interface, 
               Layer 1 Specifications: "
     ::= { dsx1ConfigEntry 5 }


Text and reference section of the new ID will be adjusted as needed.

Please comment if you have any issue with the subject.

Thanks
Orly