MAP vs Diameter
Mobile Application Part (MAP) and Diameter are both protocols used in different contexts. The Mobile Application Part (MAP) is one of the protocols in the SS7 protocol suite, which allows for the implementation many different mobile network signaling infrastructure whereas, Diameter protocol is responsible of providing an Authentication, Authorization and Accounting (AAA) framework for applications such as network access or IP mobility. Different releases of 3GPP adapted both these protocols in order to cater the evolving networks and their interworking.
Mobile Application Part (MAP)
Mobile Application Part (MAP) is a protocol which is in the Signaling System 7 (SS7) protocol stack. As shown in the figure 1, it is an application layer protocol. The key function of MAP is to connect the distributed switching elements in the core network such as providing interaction between mobile switching centers (MSC) and the static database called the Home Location Register (HLR). It basically facilitates for subscriber data management, authentication, call handling, location management, short message service (SMS) management and subscriber tracing.
It’s major function is to handle mobility procedures such as passing information of a mobile subscriber from one switching area to another. Basically these procedures involve signaling exchanges with databases.
For example, when a mobile subscriber roams into a new switching area, its subscription profile is retrieved from the subscriber’s’ Home Location Register (HLR). This is implemented using MAP information carried inside the Transaction Capabilities Application Part (TCAP) messages. The TCAP is also an SS7 application protocol that is used by various applications.
Diameter is a protocol that provides a basic framework for any kind of services which require Access, Authorization, and Accounting (AAA) or Policy support across many IP based networks. This protocol was originally derived from the RADIUS protocol which is also a protocol provides AAA services to computers in order to connect and use a network. Diameter has come up with a lot of improvements over RADIUS in different aspects. It includes numerous enhancements such as error handling and message delivery reliability. Thus, it is aiming to become the next generation Authentication, Authorization, and Accounting (AAA) protocol.
Diameter delivers data in the form of an AVP (Attribute value pairs). Most of these AVP values are associated with particular applications that employ Diameter while some of them are used by the Diameter protocol itself. These attribute value pairs are may be added randomly to diameter messages so, it restricts including any unwanted attribute value pairs which are intentionally blocked, as long as required attribute value pairs are included. These attribute value pairs are used by the base diameter protocol in order to support numerous required features.
Generally with the diameter protocol any host can be configured as either a client or a server based on network infrastructure, since diameter is designed to facilitate Peer-To-Peer architecture. With the addition of new commands or Attribute value pairs, it is also possible for the base protocol to be expanded for use in new applications. A legacy AAA protocol used by many applications might provide different functionality not provided by Diameter. Thus, the designers who use diameter for new applications have to be very careful of their requirements.
What is the difference between MAP and Diameter?
• Both protocols support signaling in the packet switched domain.
• In diameter protocol data is carried within a diameter message as a collection of attribute value pairs (AVP) whereas, MAP uses MAP parameters where various parameters dependent on the operation.
• MAP protocol supports signaling exchanges with Home Location Register (HLR) and Equipment Identity Register, whereas Diameter protocol supports AAA functions with computer networks.
• Both Protocols can operate as UMTS (Universal Mobile Telecommunications System) supported protocols in sending IMSI (International Mobile Subscriber Identity) to the HSS (Home Subscriber Server) in the process of wireless local area network (WLAN) authentication.
Diameter protocol can be expanded into new access technologies, but it is not supported by the MAP protocol.
• Both protocols can send messages related to authentication.
• MAP supports both Circuit and Packet switch domains whereas, Diameter supports only packet switch domain.
• When supporting roaming in order to enable the routing of signaling between operators both protocols use the quasi-associated mode with STPs (Signaling Transfer Points).