trate hundreds of DSL access lines onto ATM or IP trunks and then route them to rout- ers or multiservice edge switches. Also in the access environment are IADs, which provide a point of integration at the customer edge, integrating voice, data, and video networks and supporting broadband access options. The access tier also contains remote access servers, which typically provide access to remote users via analog modem or ISDN connec- tions and include dialup protocols and access control or authentication schemes. Remote access routers are used to connect remote sites via private lines or public carriers, and they provide protocol conversations between the LAN and the WAN. The Middle Tier: The Intelligent Edge The second tier involves the intelligent edge devices. These can include next-generation switches, VoIP gateways, media gateways, trunking gateways, ATM switches, IP routers, IP switches, multiservice agnostic platforms, optical networking equipment, and collaborating servers. This tier is also home to the network management stations that manage all those devices. The edge devices and the intelligent edge generally handle AAA functions. They identify the specific levels of performance required and map the proper QoS levels into the packet according to the backbone protocol. The intelligence keeps moving closer and closer to the customer, and it is actually being extended to CPE. We're trying to get away from an environment that has a lot of single-purpose net- works associated with single-purpose boxes and their own individual access lines (see Figure 10.6). As mentioned previously, there are complexities involved with acquisition, with ongoing maintenance, and with the talent pool to administer and maintain these systems. The ideal situation would be a multipurpose WAN switch that could facilitate the termination of any type of data protocol as well as facilitate aggregation at high speeds to the various optical levels (see Figure 10.7). This is what we're striving for with the intelligent edge. Traditiona