Diff-serv motivations (contd)
Diff-serv must work with IPv4.
- Costs: incompatibility…
- Redefining TOS octet.
- Compatibility w/ RFC 791 (IP precedence)
- New implementation of critical forwarding path as a “per-hop behavior”
- Opportunities: leveraging Internet protocol base
- Vendors: Opportunity for router upgrades
- Small/medium-sized providers: economic necessity.
- Large providers: view diff-serv as an intermediate solution to QoS while waiting for MPLS to integrate ATM, FR facilities and get traffic engineering features.