[cisco-voip] Cisco DTMF detection, GSM

[Oleg Shevtsov]

Hello,


Have you, guys, some experience about DTMF over GSM network?
I have problems with tones detection if someone calls from
GSM mobile phone. The problem occurs more often with digits 3,6,9
(so-called high-tones). High tone for all these digits is the same: 1477Hz.


Can you advice something?

PS: 
The network scheme is:
GSM Phone -> (GSM provider network) ===E1 PRI===> C5300


-- 
Oleg Shevtsov
Chief of NOC InterExchange Carrier
phone +380442399740
mobile +380672341642
fax +380442468910
http://www.ixcaccounting.com