Troubleshooting SCTP/M3UA connection with Cisco ITP

[Mladen Cvetkovic]

Hi,

I am trying to setup connection between Restcomm SMSC 7.0 and Cisco ITPs using SIGTRAN (no ss7 hardware cards).

SMSC is installed on Red Hat with available binaries from

https://telestax.com/restcomm-telscale-smsc-gw-7-0-released/

SMSC is started in default mode (without any simulators).

To setup connection I was using Web console available with Restcomm SMSC 7.0 installation on:

http://<smsc ip address>:8080/jss7-management-console/

I have setup SCTP Association as client towards <Cisco ITP IP address>.

I have also setup M3UA ASP Factory, (corresponding to SCTP association), corresponding AS (as SGW or signalling gateway) and ASP. Also I have setup M3UA route using allocated SMSC and ITP point codes.

After that, in Jss7 web console I have started ASP Factory that was created.

The only tracing I have got in JBOSS server logs was:

02:26:09,869 INFO  [AssociationImpl] (http-192.168.102.181-8080-6) Started Association=Association [name=client, associationType=CLIENT, ipChannelType=SCTP, hostAddress=192.168.104.15, hostPort=5853, peerAddress=192.168.104.11, peerPort=5853, serverName=, extraHostAddress=[]]

In Jss7 console we can see for only created SCTP association towards ITP that:

Name: client

Started: true

Up: false

Connected: false

Cisco ITP is configured to look towards SMSC, however execution of 

show cs7 asp

gives that connection state is down.

Some questions:

1) If we correctly setup SCTP and M3UA, would we expect more JBoss tracing to prove that connection is established (or not)? Is there a way to get more useful tracing?

2) Would we be able to see that connection is established if we only configured SCTP and M3UA without SCCP or TCAP/MAP?

3) What determines if in SCTP we will setup association in client or server mode? When are we supposed to use SCTP server option?

4)  When looking into http://<smsc ip address>:8080/jss7-management-console/ we can see that selection of Linkset does not provide any option to add Linkset properties - is that disabled/not needed for SMSC configuration?

5) Apart from JBoss tracing and Whireshark PCAP generation, are there any other options for troubleshooting SCTP/M3UA connectivity problems?

6) Do we miss some other relevant node or parameter in configuration?

Thanks in advance.

Regards,

Mladen

[Sergey Vetyutnev]

Hello,

the most probably you have wrongly configured SCTP / M3UA parts or you have an IP communication problem. Also pay attention that you need to configure SCCP part.

> 1) If we correctly setup SCTP and M3UA, would we expect more JBoss tracing to prove that connection is established (or not)? Is there a way to get more useful tracing?

when a m3ua connection becomes established you will have an announesement in log.

> 2) Would we be able to see that connection is established if we only configured SCTP and M3UA without SCCP or TCAP/MAP?

for bringing up of SCTP / m3ua link it is enouph to configure SCTP / m3ua levels

> 3) What determines if in SCTP we will setup association in client or server mode? When are we supposed to use SCTP server option?

one of a peer must be a client another - a server. So you need to check a SS7 peer's config / configure a peer

> 4)  When looking into http://<smsc ip address>:8080/jss7-management-console/ we can see that selection of Linkset does not provide any option to add Linkset properties - is that disabled/not needed for SMSC configuration?

Section "linkset" is needed only if you use dahdi SS7 cards. Do not touch it if you use m3ua.

> 5) Apart from JBoss tracing and Whireshark PCAP generation, are there any other options for troubleshooting SCTP/M3UA connectivity problems?

try "ping" option or tool like it for a network healf checking and check your configs.

> 6) Do we miss some other relevant node or parameter in configuration?

[Mladen Cvetkovic]

Hi Sergey,

Thank you very much for the quick and useful suggestions that helped us progress further.

In our case it turned out that wireshark tracing on ITP side has pointed to the problem with rejection of packets sent from ITP towards SMSC (while SCTP packets from SMSC were reaching ITP without any problems). 

Once we adjusted rules for SCTP packets with iptables command, we started to see SCTP packet exchange working well. Also related SCTP association in JSS7 web console has become marked as fully active. We are now moving to configuring upper layers of SS7 stack.

Regards,

Mladen