A of deterministic Ethernet is used on the Boeing 787 Dreamliner. Multiple switches can be bridged together in a cascaded star topology. This type of network can significantly reduce wire runs, thus the weight of the aircraft. In addition, AFDX can provide quality of service and dual link redundancy. Overview of AFDX AFDX adopted concepts such as the token bucket from the telecom standards, Asynchronous Transfer Mode (ATM), to fix the shortcomings of IEEE 802.3 Ethernet. By adding key elements from ATM to those already found in Ethernet, and constraining the specification of various options, a highly reliable full-duplex deterministic network is created providing guaranteed bandwidth and quality of service (QoS). Through the use of full-duplex Ethernet, the possibility of transmission collisions is eliminated. The network is designed in such a way that all critical traffic is prioritized using QoS policies so delivery, latency, and jitter are all guaranteed to be within set parameters. A highly intelligent switch, common to the AFDX network, is able to buffer transmission and reception packets. Through the use of twisted pair or fiber optic cables, full-duplex Ethernet uses two separate pairs or strands for transmitting and receiving the data. AFDX extends standard Ethernet to provide high data integrity and deterministic timing. Further a redundant pair of networks is used to improve the system integrity (although a virtual link may be configured to use one or the other network only). It specifies interoperable functional elements at the following OSI reference model layers: Data link (MAC and virtual link addressing concept); Network (IP and ICMP); Transport (UDP and optionally TCP) Application (network) (sampling, queuing, SAP, TFTP and SNMP). The main elements of an AFDX network are: AFDX end systems AFDX switches AFDX links Virtual links The central feature of an AFDX network are its virtual links (VL). In one abstraction, it is possible to visualise the VLs as an ARINC 429 style network each with one source and one or more destinations. Virtual links are unidirectional logic paths from the source end-system to all of the destination end-systems. Unlike that of a traditional Ethernet switch which switches frames based on the Ethernet destination or MAC address, AFDX routes packets using a virtual link ID, which is carried in the same position in an AFDX frame as the MAC destination address in an Ethernet frame. However, in the case of AFDX, this virtual link ID identifies the