Slide 27 of 37
Notes:
It is also unrealistic to attempt to provide end-to-end QoS in the Internet with any particular link-layer technology, such as ATM, since a packet in flight between a source and destination may traverse any number of link-layer transport media types (e.g. Ethernet, point-to-point serial links).
This is where the “most common denominator” philosophy comes into play. Since the “common bearer service” in the Internet is the TCP/IP protocol suite, this is the natural place to do traffic differentiation.
