[asterisk-ss7] Debugging SS7

[Matthew Fredrickson]

Dmitri Sologoubenko wrote:
> Hello!
> 
> I'm a asterisk<>ss7 newbie, so need some help :)
> 
> I've changed and recompiled ss7linktest utility distributed in libss7
> trunk, because it was working only with "national" network indication,
> while my ss7 telco uses "national_spare".
> 
> How can I post the modified source or a diff patch so people can set
> network indication type from command line?

You can post it to bugs.digium.com.  That's where contributions for 
libss7 are managed.

> 
> And, how can I interpret the output of my ss7linktest?
> 

This is a verbose output of a lot of low level messaging traffic for SS7 
link initialization.  You might want to get a good book on SS7 if you 
are interested in the low level aspects of it.  I recommend Cisco's 
"Signaling System No. 7 (SS7/C7) Protocol, Architecture, and Services" 
book.  It's very good, and very understandable.

> Starting link 1
> Link state change: IDLE -> NOTALIGNED
> Len = 4 [ ff ff 01 00 ]
> FSN: 127 FIB 1
> BSN: 127 BIB 1
>>> [0] LSSU SIO
> 
> Len = 4 [ ff ff 01 00 ]
> FSN: 127 FIB 1
> BSN: 127 BIB 1
> <[0] LSSU SIO
> 
> Link state change: NOTALIGNED -> ALIGNED
> Len = 4 [ ff ff 01 02 ]
> FSN: 127 FIB 1
> BSN: 127 BIB 1
>>> [0] LSSU SIE
> 
> Len = 4 [ ff ff 01 02 ]
> FSN: 127 FIB 1
> BSN: 127 BIB 1
> <[0] LSSU SIE
> 
> Link state change: ALIGNED -> PROVING
> T4 expired!
> Link state change: PROVING -> ALIGNEDREADY
> Len = 3 [ ff ff 00 ]
> FSN: 127 FIB 1
> BSN: 127 BIB 1
>>> [0] FISU
> 
> Len = 3 [ ff ff 00 ]
> FSN: 127 FIB 1
> BSN: 127 BIB 1
> <[0] FISU
> 
> Link state change: ALIGNEDREADY -> INSERVICE
> [0] MTP2 link up
> Len = 9 [ ff 80 06 c0 04 80 f0 02 17 ]
> FSN: 0 FIB 1
> BSN: 127 BIB 1
>>> [0] MSU
> [ ff 80 06 ]
>         Network Indicator: 3 Priority: 0 User Part: NET_MNG (0)
>         [ c0 ]
>         OPC 3010 DPC 4 SLS 0
>         [ 04 80 f0 02 ]
>         H0: 7 H1: 1
>         Message type: TRA
>         [ 17 ]
> 
> Len = 20 [ ff 81 11 c1 04 80 f0 02 11 a0 32 35 36 34 32 38 36 32 38 38 ]
> FSN: 1 FIB 1
> BSN: 127 BIB 1
>>> [0] MSU
> [ ff 81 11 ]
>         Network Indicator: 3 Priority: 0 User Part: STD_TEST (1)
>         [ c1 ]
>         OPC 3010 DPC 4 SLS 0
>         [ 04 80 f0 02 ]
>         H0: 1 H1: 1
>         [ 11 ]
> 
> Len = 25 [ ff 80 16 c1 c2 cb 00 00 11 f0 aa aa aa aa aa aa aa aa aa aa
> aa aa aa aa aa ]
> FSN: 0 FIB 1
> BSN: 127 BIB 1
> <[0] MSU
> [ ff 80 16 ]
>         Network Indicator: 3 Priority: 0 User Part: STD_TEST (1)
>         [ c1 ]
>         OPC 3 DPC 3010 SLS 0
>         [ c2 cb 00 00 ]
>         H0: 1 H1: 1
>         [ 11 ]
> 
> Len = 25 [ 80 82 16 c1 03 80 f0 02 21 f0 aa aa aa aa aa aa aa aa aa aa
> aa aa aa aa aa ]
> FSN: 2 FIB 1
> BSN: 0 BIB 1
>>> [0] MSU
> [ 80 82 16 ]
>         Network Indicator: 3 Priority: 0 User Part: STD_TEST (1)
>         [ c1 ]
>         OPC 3010 DPC 3 SLS 0
>         [ 03 80 f0 02 ]
>         H0: 1 H1: 2
>         [ 21 ]
> 
> [0] --- SS7 Up ---
> Len = 14 [ 80 83 0b c5 04 80 f0 12 01 00 17 01 01 17 ]
> FSN: 3 FIB 1
> BSN: 0 BIB 1
>>> [0] MSU
> [ 80 83 0b ]
>         Network Indicator: 3 Priority: 0 User Part: ISUP (5)
>         [ c5 ]
>         OPC 3010 DPC 4 SLS 1
>         [ 04 80 f0 12 ]
>                 CIC: 1
>                 [ 01 00 ]
>                 Message Type: GRS
>                 [ 17 ]
>                 --VARIABLE LENGTH PARMS[1]--
>                 Range and status:
>                         Range: 23
>                         [ 01 17 ]
> 
> 
> What is happening on my SS7 link?

Your link came up. (----- SS7 UP ------)

> 
> Should I run the ss7linktest utility only on bchan number or freely on
> any channel number?

It is only for your signalling channel.  So whatever Zap channel has 
your signalling on, that is the channel you should run it on.

-- 
Matthew Fredrickson
Software/Firmware Engineer
Digium, Inc.