[asterisk-ss7] ss7-27-knk: Bringing MTP3 up ?

[Pavel Troller]

Hi!
  I'm new in this list, I was "invited" by Kaloyan to post there in case
of some questions or problems regarding the improved SS7 support in 
chan_dahdi.
  My first finding is, that now I can't bring MTP3 up. It seems, that the
MTP3 layer now relies on receiving the TRA message to proceed with
initialization. However, in our national SS7 network, these messages
are not used. Sending successful SLTM/SLTA both ways is enough to
initialize the linkset.
  I'm trying to establish a direct linkset to EWSD (no STPs between). AFAIK,
EWSD with Czech national SS7 doesn't send TRA messages and doesn't require
their receipt. I know EWSD reasonably well and I don't know any method, how
to force it to send TRAs.
  EWSD sees the linkset as up and tries to send GRS on ISUP, which is
refused by Asterisk, because its MTP3 is still marked as down.

Some diagnostics:
Asterisk side:

testomt*CLI> ss7 show linkset 1
SS7 flags: 0x0
SS7 linkset 1 status: Down
SS7 calling nai: -1
SS7 called nai: -1
SS7 nationalprefix:
SS7 internationalprefix: 00
SS7 unknownprefix:
SS7 networkroutedprefix:
SS7 subscriberprefix:
Switch type: ITU
Our point code: 11
SLS shift: 0
numlinks: 1
numsps: 1
  ---------------------------------
  Adjacent SP PC: 1026 STATE: DOWN
  TRA:  SENT    T19: not running T21: not running
  Routes:
    DPC       State        T6       T10
  Link ADJ_PC:SLC: 1026:0 NetMngSLS: 0
    State:      INSERVICE,  UP
    STD Test:  passed
    Got, sent :
    Inhibit:
    Changeover: NO
    Tx buffer:  0
    Tx queue:   0
    Retrans pos 0
    CO buffer:  0
    CB buffer:  0
    Last FSN:   122
    MTP3timers:

EWSD side:
DISPC7LSET:LSNAM=LS.ASTDEVEL;                                     EXEC'D

CCS7 -- DISPLAY SIGN. ELEMENTS -- SIGNALING LINK SET

LSNAM        DPC           NETIND LSNO LSK OST INH EST ALTYPE   PERLTEST
------------+-------------+------+----+---+---+---+---+--------+--------
LS.ASTDEVEL   0- 11        NAT0    13   0  ACT NO  ACT CCSLSNAC ON

INTERRUPTION TEXT JOB 2275



CONTINUATION TEXT 0001

TSTCZ/AD061D1882E/GTS1632P169-3590/003                13-03-26  09:28:27
2275 10.2.25.1/PATR                2871/03922

CCS7 -- DISPLAY SIGN. ELEMENTS -- SIGNALING LINK

LSNAM: LS.ASTDEVEL
DPC  :  0- 11         NETIND: NAT0

LCOD LINKNO SILTNO LTYPE   OST IST EST  REAS
----+------+------+-------+---+---+----+------
  0     10     13  D64BWM  ACT NOT ACT

INTERRUPTION TEXT JOB 2275



CONTINUATION TEXT 0002

TSTCZ/AD061D1882E/GTS1632P169-3590/003                13-03-26  09:28:27
2275 10.2.25.1/PATR                2871/01074

CCS7 -- DISPLAY SIGN. ELEMENTS  -- ACTUAL LINKS IN SIGN. LINK SET

LSNAM         L1 L2 L3 L4 L5 L6 L7 L8 L9 L10 L11 L12 L13 L14 L15 L16
--------------------------------------------------------------------
LS.ASTDEVEL   0  0  0  0  0  0  0  0  0  0   0   0   0   0   0   0

END JOB 2275

You can see ACT under OST in the linkset display, which means "Active".


My Asterisk ss7 config:
usecallingpres=1

signalling=ss7
;
; Variant of SS7 signalling:
; Options are itu and ansi
ss7type=itu

; SS7 Called Nature of Address Indicator
;
; unknown:        Unknown
; subscriber:     Subscriber
; national:       National
; international:  International
; dynamic:        Dynamically selects the appropriate dialplan
;
ss7_called_nai=dynamic
;
; SS7 Calling Nature of Address Indicator
;
; unknown:        Unknown
; subscriber:     Subscriber
; national:       National
; international:  International
; dynamic:        Dynamically selects the appropriate dialplan
;
ss7_calling_nai=dynamic
;
;
; sample 1 for Germany
ss7_internationalprefix=00
ss7_nationalprefix=
ss7_subscriberprefix=
ss7_unknownprefix=
;

; This option is used to disable automatic sending of ACM when the call is started
; in the dialplan.  If you do use this option, you will need to use the Proceeding()
; application in the dialplan to send ACM.
ss7_explictacm=yes

; ============== TST CZ ===============

; All settings apply to linkset 1
linkset=1
slc=0

; Point code of the linkset.  For ITU, this is the decimal number
; format of the point code.  For ANSI, this can either be in decimal
; number format or in the xxx-xxx-xxx format
pointcode=11

; Point code of node adjacent to this signalling link (Possibly the STP between you and
; your destination).  Point code format follows the same rules as above.
adjpointcode=1026

; Default point code that you would like to assign to outgoing messages (in case of
; routing through STPs, or using A links).  Point code format follows the same rules
; as above.
defaultdpc=1026

; What the MTP3 network indicator bits should be set to.  Choices are
; national, national_spare, international, international_spare
networkindicator=national


; First signalling channel
sigchan=1

group=1

context=from_ss7

faxdetect=no

; Begin CIC (Circuit indication codes) count with this number
cicbeginswith=2
; Channels to associate with CICs on this linkset
channel=2-5

setvar=FAXOPT(gateway)=yes

Thank you for the patience while reading this.
With regards,
  Pavel