municipalities. This is because their devices often operate over different portions of the radio frequency (RF) spectrum than those of other departments or cities. Departments within large municipalities and the federal government have not always been able to contact other public safety personnel because of this issue. This has been a huge problem during widespread national disasters (the problem gained particular notoriety during the aftermath of the attacks on September 11, 2001). To solve this problem for agencies taking advantage of this service, the car- rier performs the compatibility conversions by using equipment in its network. Managed Services and Telepresence in Conjunction with MPLS Because of the end-to-end prioritization capabilities and network monitoring that MPLS provides, it is particularly suitable for certain managed services. Telepresence, a high-end video conferencing service, requires priority service on all network points over which it travels for guaranteed high quality. Rather than manage their own confer- ences, multisite and international organizations often outsource their video conferenc- ing to their MPLS network provider. Most of the enterprise sites have their own conference rooms, specially equipped with video equipment. Staff members in other sites can participate in video confer- ences at public rooms connected to the carrier's MPLS network. In addition to manag- ing the video conference, the carrier often provides the bridging equipment needed to connect more than two sites together in a video conference. The carrier sets up conferences and monitors audio and video quality during the conference. This elimi- nates the need for customers to train people on how to use the equipment. It also does away with the need to purchase and maintain bridging equipment. Using Digital Subscriber Line for Internet Access This is particularly useful for companies where sites might use incompatible video equipment, and international sites where training staff members is difficult. It has become 