We have the following U1980 with firmware version V200R003.
The customer already had long numbers configured but connected to SIP accounts beginning with 53XX.
However, when he was calling the long numbers configured on the 30XX SIP account, they were not connecting to the telephone.
I requested a remote ression to the customer so I could analyze the calls and also we check the configuration on the U1980.
I found that the PBX was already configured with some specifications (rules) from a previous maintenance, done by a third party company.
1. The first rule configured on the PBX was a DELETE rule, thus, removing the first DIGIT of every source number. Therefore, when calling a long number associated with a SIP account for example 53XX it was removing the digit 5 and so on, on every incoming call.
2. The second rule was an insert rule, however, this rule was associated only with prefix 3, which ment it was actually relating to the SIP accounts range 53XX, first rule was removing the digit 5, leaving 3, second rule was adding back the 5, only to prefix 3.
Because of this configuration the calls to SIP accounts 53XX were connecting, I do not know why the customer had this made in the first place and I did not change it just as this maybe would have impated other services.
This ment that when someone was calling on the other long numbers associated with SIP accounts 30XX the first digit was removed leaving the number beginning with 0 and therefore, relating with prefix 0 which was for national calls.
There was a delete rule removing the first digit of incoming source number and calls could not connect to the designated SIP account.
For this issue to be solved I made some additional configuration without modifying too much the previous one.
Deleted the 0 and 00 national and internaltional prefixes(created different ones), which were created by me and added a new prefix 0 intra-office call, created a new insert rule to add the 3 in front of the number and finally associated this rule with prefix 0. This way the called SIP account number was complete and the call was connecting.