I am receiving calls from a DID provider over the public Internet. The platform that the callers access is a calling card one so once the call is established the caller is asked for a PIN. Since the last month I noticed that we are receiving a large number of duplicated digits that makes the call fail. The provider confirms that no change was made at his equipment neither we change anything in ours so my question is:
What can be causing this behavior? Could it be a router in the path between the provider and us? Any sugestion will be appreciated.