Re: [Skunkworks] Connection problem or invalid MMI code

@Joram, I've encountered some operators who parse most of their error codes into the pesky "*...invalid MMI...*" for display on the handset (BTW the exact notification varies from one phone manufacturer to the next). The exact spread of that 40% failure rate will give pointers to the nature of the problem. - Is it 40% of all attempts from the same handset? If so, there could be a resource problem with one of the signalling stack involved; particularly on very busy networks. - Is it failing consistently for some select handsets, translating to the 40%? If so, check the Data Coding Scheme at play. The USSD-GW vendor may need to look for ways to maintain the DCS of the incoming traffic. Either way, an on-the-wire trace (snoop/tcpdump/wireshark etc) between the communicating entities never lies - that's my mantra [?] PS : You may need to check the content of the messages at play....most equipment vendors do not take raw special characters kindly. Tony.

It is a Linux box. Tell me the command to use tcpdump -w /tmp/working_USSD.pcap -s 0 -i any host 10.x.y.z On Thu, Sep 11, 2014 at 6:04 PM, Tony Likhanga via skunkworks < skunkworks@lists.my.co.ke> wrote:
@Joram,
I've encountered some operators who parse most of their error codes into the pesky "*...invalid MMI...*" for display on the handset (BTW the exact notification varies from one phone manufacturer to the next).
The exact spread of that 40% failure rate will give pointers to the nature of the problem.
- Is it 40% of all attempts from the same handset? If so, there could be a resource problem with one of the signalling stack involved; particularly on very busy networks. - Is it failing consistently for some select handsets, translating to the 40%? If so, check the Data Coding Scheme at play. The USSD-GW vendor may need to look for ways to maintain the DCS of the incoming traffic.
Either way, an on-the-wire trace (snoop/tcpdump/wireshark etc) between the communicating entities never lies - that's my mantra [?]
PS : You may need to check the content of the messages at play....most equipment vendors do not take raw special characters kindly.
Tony.
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If you know the exact interface use: *tcpdump -n -i <interface_name> -s 10240 -w /tmp/working_USSD.pcap* Else, to capture packets across all available interfaces you may just use : *tcpdump -vvv -i any -s 10240 -w /tmp/working_USSD.pcap* I'm assuming that this is a Sigtran integration. If it's a traditional SS7 set-up using E1 links, then you may need to check with the stack vendor on how to capture the SS7 packets. Tony.
participants (2)
-
Joram Gachuiri
-
Tony Likhanga