[Asterisk-Users] SS7 signaling/Softswitch

CW_ASN - Gus cw_asn at fibertel.com.ar
Tue Oct 28 06:29:08 MST 2003


> Close.  Normally, at least in Qwest-land, third-party VM provider systems
dial
> into the switch and give it a DN and a MWI on-or-off command.  If the DN
is
> serviced by that switch, it turns the message waiting indicator (stutter
> dialtone, MW light or both) on or off.  If the number is on a remote
switch, the
> information gets sent over the SS7 network to the other Qwest switch.  I
haven't
> seen MWI specifically mentioned as standard message sent via SS7, but
obviously
> it's being done.  I don't know enough about the details of SS7 to know
what
> messages can be sent or if there's a generic container message that can be
used
> for anything.
---> Some international implementations do this in more easy, but more
faulty... when the switchs make a call diversion for a VoiceMail system, its
starts to make a stutter tone, or send MWI indications to the phone. If the
subscriber dials to VoiceMailMain application to retrieve the messages, the
switch stops the stutter tone, or anything. I know, is a crap, but in some
coutries it was implemented in this way.

>  From my research that's correct.  The PRI's D channel doesn't speak SS7,
> although the protocols are extremely similar in function.  Everything I've
read
> says that getting out-of-band signalling to the CP was the whole point in
> creating ISDN.  What I'm trying to find out is if there's some way to send
a D
> channel message that would get translated directly into SS7.  The ISUP
layer of
> the SS7 protocol is the ISDN User Part - is that designed to encapsulate
CLASS
> messages?
----> No, you don't "directly" send information between PRI and ISUP
message... To understand correctly this, I send a complete ISUP trace.

>
> Take ANI for example.  Your PRI sends the ANI information to the near end
switch
> over the D channel which then passes it on (without verification, I might
add)
> on to the destination switch via SS7.  This is a case where the
information is
> transferred directly.  What about LIDB lookups or route information?  Is
there
> any way to get this, which is definitely available over SS7, from the D
channel?
----> This is not 100% accured... In all implementations that I saw, you can
send any ANI to PSTN switch in PRI, but this switch makes a check to
determine if your ANI is valid, and if your ANI is your real ANI!!! This is
the most important check.

> > So, the proper answer is that if you really want to implement this PRI -
SS7
> > - PRI message, you should really be talking to your nearest CO Engineer
or
> > Telco Enterprise Business Office where they handle this all the time for
> > enterprise call center applications.
----> Mhh... is really hard...

> > On the other hand, maybe Gus could contribute a regular tutorial on how
he's
> > got various things interconnected.  The more the info, the better.  Gus
once
> > asked if we want the plethora of info he can provide.  I vote yes.
----> Sure! I have some documents very useful. Please give me some ideas to
know what things you like.

Regards,

Gus


-------------- next part --------------
+---------+---------------------------------------------+------------------------------------+
|BITMASK  |ID Name                                      |Comment or Value                    |
+---------+---------------------------------------------+------------------------------------+
|10/28 08:36:03,589  1:B (Rx):16  MSU  IAM  8971  16289  25  `54441111f`  `6751010866`       |
|MTP Level 2 (MTP-L2)  MSU (= Message Signal Unit)                                           |
|Message Signal Unit                                                                         |
|-0101101 |Backward Sequence Number                     |45                                  |
|1------- |Backward Indicator Bit                       |1                                   |
|-0110100 |Forward Sequence Number                      |52                                  |
|0------- |Forward Indicator Bit                        |0                                   |
|--100110 |Length Indicator                             |38                                  |
|00------ |Spare                                        |0                                   |
|----0101 |Service Indicator                            |ISDN User Part                      |
|--00---- |Sub-Service: Priority                        |Spare/priority 0 (U.S.A. only)      |
|10------ |Sub-Service: Network Ind                     |National message                    |
|**b14*** |Destination Point Code                       |16289                               |
|**b14*** |Originating Point Code                       |8971                                |
|CCITT BLUE BOOK ISDN User Part (ISUP)  IAM (= Initial Address)                              |
|Initial Address                                                                             |
|1001---- |Signalling Link Selection                    |9                                   |
|**b12*** |Circuit Ident Code                           |25                                  |
|0000---- |Spare                                        |0                                   |
|00000001 |Message Type                                 |1                                   |
|------00 |Satellite Indicator                          |No satellite circuit                |
|----00-- |Continuity Check Indicator                   |Cont Check not required             |
|---0---- |Echo Suppressor Indicator                    |O/G half echo supp not included     |
|000----- |Spare                                        |0                                   |
|-------0 |Nat./Internat. Indicator                     |Treat as a national call            |
|-----00- |End-to-End Method Ind                        |No end-to-end method available      |
|----0--- |Interworking Indicator                       |No interworking encountered         |
|---0---- |End/End Information Ind                      |No end-to-end info available        |
|--1----- |ISDN User Part Indicator                     |ISDN-UP used all the way            |
|00------ |ISDN-UP Preference Ind                       |ISDN-UP preferred all the way       |
|-------0 |ISDN Access Indicator                        |Originating access non-ISDN         |
|-----00- |SCCP Method Indicator                        |No indication                       |
|00000--- |Spare                                        |0                                   |
|00001010 |Calling Party's Category                     |Ordinary calling subscriber         |
|00000011 |Transmission Medium Reqt                     |3.1 kHz audio                       |
|00000010 |Pointer to parameter                         |2                                   |
|00001001 |Pointer to parameter                         |9                                   |
|Called party number                                                                         |
|00000111 |Parameter Length                             |7                                   |
|-0000001 |Nature of Address                            |Subscriber number                   |
|1------- |Odd/Even Indicator                           |Odd number of address signals       |
|----0000 |Spare                                        |0                                   |
|-001---- |Numbering Plan Indicator                     |ISDN Nr.plan (E.164/E.163)          |
|0------- |Internal Network No. Ind                     |Routing to INN allowed              |
|**b36*** |Called Address Signals                       |`54441111f`                         |
|0000---- |Filler                                       |0                                   |
|Calling party number                                                                        |
|00001010 |Parameter Name                               |Calling Party Number                |
|00000111 |Parameter Length                             |7                                   |
|-0000011 |Nature of Address                            |National (significant) number       |
|0------- |Odd/Even Indicator                           |Even number of address signals      |
|------01 |Screening Indicator                          |User provided, verified passed      |
|----00-- |Presentation Restr. Ind                      |Presentation allowed                |
|-001---- |Numbering Plan Indicator                     |ISDN Nr.plan (E.164/E.163)          |
|0------- |Callg No. Incomplete Ind                     |Complete                            |
|***B5*** |Calling Address Signals                      |`6751010866`                        |
|User service information                                                                    |
|00011101 |Parameter Name                               |User service information            |
|00000011 |Parameter Length                             |3                                   |
|---10000 |Info Transfer Capability                     |3.1 kHz audio                       |
|-00----- |Coding Standard                              |CCITT-standardized coding           |
|1------- |Extension Indicator 1                        |Last octet                          |
|---10000 |Information Transfer Rate                    |64 kbit/s                           |
|-00----- |Transfer Mode                                |Circuit mode                        |
|1------- |Extension Indicator 2                        |Last octet                          |
|---00011 |User Info Layer 1 Protcol                    |G.711 A-law                         |
|-01----- |Layer Identification                         |User info layer 1 protocol          |
|1------- |Extension Indicator 3                        |Last octet                          |
|End of optional parameters                                                                  |
|00000000 |End of Optional Params                       |0                                   |

+---------+---------------------------------------------+------------------------------------+
|BITMASK  |ID Name                                      |Comment or Value                    |
+---------+---------------------------------------------+------------------------------------+
|10/28 08:36:08,363  1:A (Rx):16  MSU  ACM  16289  8971  25                                  |
|MTP Level 2 (MTP-L2)  MSU (= Message Signal Unit)                                           |
|Message Signal Unit                                                                         |
|-0111110 |Backward Sequence Number                     |62                                  |
|0------- |Backward Indicator Bit                       |0                                   |
|-0111101 |Forward Sequence Number                      |61                                  |
|1------- |Forward Indicator Bit                        |1                                   |
|--001011 |Length Indicator                             |11                                  |
|00------ |Spare                                        |0                                   |
|----0101 |Service Indicator                            |ISDN User Part                      |
|--00---- |Sub-Service: Priority                        |Spare/priority 0 (U.S.A. only)      |
|10------ |Sub-Service: Network Ind                     |National message                    |
|**b14*** |Destination Point Code                       |8971                                |
|**b14*** |Originating Point Code                       |16289                               |
|CCITT BLUE BOOK ISDN User Part (ISUP)  ACM (= Address Complete)                             |
|Address Complete                                                                            |
|1001---- |Signalling Link Selection                    |9                                   |
|**b12*** |Circuit Ident Code                           |25                                  |
|0000---- |Spare                                        |0                                   |
|00000110 |Message Type                                 |6                                   |
|------10 |Charge Indicator                             |Charge                              |
|----01-- |Called Party's Status Ind                    |Subscriber free                     |
|--00---- |Called Party's Category                      |No indication                       |
|00------ |End-to-End Method Ind                        |No end-to-end method available      |
|-------1 |Interworking Indicator                       |Interworking encountered            |
|------0- |End/End Information Ind                      |No end-to-end info available        |
|-----0-- |ISDN User Part Indicator                     |ISDN-UP not used all the way        |
|----0--- |Holding Indicator                            |Holding not requested               |
|---0---- |ISDN Access Indicator                        |Terminating access non-ISDN         |
|--0----- |Echo Control Device Ind                      |I/C half echo supp not included     |
|00------ |SCCP Method Indicator                        |No indication                       |
|00000000 |Pointer to parameter                         |0                                   |

+---------+---------------------------------------------+------------------------------------+
|BITMASK  |ID Name                                      |Comment or Value                    |
+---------+---------------------------------------------+------------------------------------+
|10/28 08:36:09,815  1:A (Rx):16  MSU  ANM  16289  8971  25                                  |
|MTP Level 2 (MTP-L2)  MSU (= Message Signal Unit)                                           |
|Message Signal Unit                                                                         |
|-0111111 |Backward Sequence Number                     |63                                  |
|0------- |Backward Indicator Bit                       |0                                   |
|-1000001 |Forward Sequence Number                      |65                                  |
|1------- |Forward Indicator Bit                        |1                                   |
|--001001 |Length Indicator                             |9                                   |
|00------ |Spare                                        |0                                   |
|----0101 |Service Indicator                            |ISDN User Part                      |
|--00---- |Sub-Service: Priority                        |Spare/priority 0 (U.S.A. only)      |
|10------ |Sub-Service: Network Ind                     |National message                    |
|**b14*** |Destination Point Code                       |8971                                |
|**b14*** |Originating Point Code                       |16289                               |
|CCITT BLUE BOOK ISDN User Part (ISUP)  ANM (= Answer Message)                               |
|Answer Message                                                                              |
|1001---- |Signalling Link Selection                    |9                                   |
|**b12*** |Circuit Ident Code                           |25                                  |
|0000---- |Spare                                        |0                                   |
|00001001 |Message Type                                 |9                                   |
|00000000 |Pointer to parameter                         |0                                   |

+---------+---------------------------------------------+------------------------------------+
|BITMASK  |ID Name                                      |Comment or Value                    |
+---------+---------------------------------------------+------------------------------------+
|10/28 08:36:40,768  1:B (Rx):16  MSU  REL  8971  16289  25      Normal call clearing        |
|MTP Level 2 (MTP-L2)  MSU (= Message Signal Unit)                                           |
|Message Signal Unit                                                                         |
|-1010100 |Backward Sequence Number                     |84                                  |
|1------- |Backward Indicator Bit                       |1                                   |
|-0101101 |Forward Sequence Number                      |45                                  |
|0------- |Forward Indicator Bit                        |0                                   |
|--001101 |Length Indicator                             |13                                  |
|00------ |Spare                                        |0                                   |
|----0101 |Service Indicator                            |ISDN User Part                      |
|--00---- |Sub-Service: Priority                        |Spare/priority 0 (U.S.A. only)      |
|10------ |Sub-Service: Network Ind                     |National message                    |
|**b14*** |Destination Point Code                       |16289                               |
|**b14*** |Originating Point Code                       |8971                                |
|CCITT BLUE BOOK ISDN User Part (ISUP)  REL (= Release)                                      |
|Release                                                                                     |
|1001---- |Signalling Link Selection                    |9                                   |
|**b12*** |Circuit Ident Code                           |25                                  |
|0000---- |Spare                                        |0                                   |
|00001100 |Message Type                                 |12                                  |
|00000010 |Pointer to parameter                         |2                                   |
|00000000 |Pointer to parameter                         |0                                   |
|Cause indicators                                                                            |
|00000010 |Parameter Length                             |2                                   |
|----0010 |Location                                     |Public net serving local user       |
|---0---- |Spare                                        |0                                   |
|-00----- |Coding Standard                              |CCITT standard                      |
|1------- |Extension Indicator 1                        |Last octet                          |
|-0010000 |Cause Value                                  |Normal call clearing                |
|1------- |Extension Indicator 2                        |Last octet                          |

+---------+---------------------------------------------+------------------------------------+
|BITMASK  |ID Name                                      |Comment or Value                    |
+---------+---------------------------------------------+------------------------------------+
|10/28 08:36:40,819  1:A (Rx):16  MSU  RLC  16289  8971  25                                  |
|MTP Level 2 (MTP-L2)  MSU (= Message Signal Unit)                                           |
|Message Signal Unit                                                                         |
|-0101101 |Backward Sequence Number                     |45                                  |
|0------- |Backward Indicator Bit                       |0                                   |
|-1010110 |Forward Sequence Number                      |86                                  |
|1------- |Forward Indicator Bit                        |1                                   |
|--001001 |Length Indicator                             |9                                   |
|00------ |Spare                                        |0                                   |
|----0101 |Service Indicator                            |ISDN User Part                      |
|--00---- |Sub-Service: Priority                        |Spare/priority 0 (U.S.A. only)      |
|10------ |Sub-Service: Network Ind                     |National message                    |
|**b14*** |Destination Point Code                       |8971                                |
|**b14*** |Originating Point Code                       |16289                               |
|CCITT BLUE BOOK ISDN User Part (ISUP)  RLC (= Release Complete)                             |
|Release Complete                                                                            |
|1001---- |Signalling Link Selection                    |9                                   |
|**b12*** |Circuit Ident Code                           |25                                  |
|0000---- |Spare                                        |0                                   |
|00010000 |Message Type                                 |16                                  |
|00000000 |Pointer to parameter                         |0                                   |



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