IP phones cannot place calls with each other. For example, when 95000 (an IP number) calls 43800 (an IP number), an announcement indicating the called number does not exist is played.
Run the following commands to delete the first six digits of the linked prefix.
config add predeal index 5 changetype delete changepos 0 changelen 6
config modify prefix dn 777777028438 callcategory basic callattribute inter cusattribute cus1 cldpredeal yes cldindex 5 min 1 max 32
The first nine digits of the linked prefix are removed. Therefore, the called number changes to 43800 instead of 02843800, leading to call failure.