In {TAIL ~ an internet telephony system}, toll free service and {HEAD ~ the calls} that are accepted and paid for can be specified by the IP telephony system user to be limited according to the calling partys identity, time of day, day of week or other criteria 
In
In { TAIL ~ an internet telephony system } , toll free service and { HEAD ~ the calls } that are accepted and paid for can be specified by the IP telephony system user to be limited according to the calling partys identity , time of day , day of week or other criteria
REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH