The object specifies the prefix of the incoming Dialed
Number Identification Service (DNIS) digits for the peer.
The DNIS digits prefix is used to match with the incoming
DNIS number for incoming call discrimination. If the
digits in this object are matched with incoming DNIS
number, the associated dialCtlPeerCfgInfoType in RFC 2128
will be used as a call discriminator for differentiating
speech, data, fax, video or modem calls.