1. Possible Broadband Deployments Post IPv4 “Completion” Alain Durand, Work in progress #include <std_disclaimer>

2. Post IPv4 Completion • Global IPv4 addresses will no longer be available in amounts large enough to sustain current customer provisioning model. (One global IPv4 address shared by several devices in one home) • The “Internet” edges will still mostly be IPv4. • Many hosts in the home (Win 9.x, XP,…) are IPv4-only. • They will not function in an IPv6 only environment. • Few of those hosts will upgrade to Windows Vista. • Content servers (web, Mail,…) hosted on the Internet by many different parties will take time to upgrade to support IPv6.

3. Lots of broken paths… Plan A: Deploy IPv6 ISP Internet CMTS CMTS IPv6 IPv6 provisionedHome Gateway IPv6 provisionedHome Gateway IPv6 provisionedHome Gateway IPv4 Legacy Device 192.168/16 192.168/16 192.168/16 IPv6-only Device

4. Post IPv4 Completion • Global IPv4 addresses will no longer be available in amounts large enough to sustain current customer provisioning model. (One global IPv4 address shared by several devices in one home) • The “Internet” edges will still mostly be IPv4. • Many hosts in the home (Win 9.x, XP,…) are IPv4-only. • They will not function in an IPv6 only environment. • Few of those hosts will upgrade to Windows Vista. • Content servers (web, Mail,…) hosted on the Internet by many different parties will take time to upgrade to support IPv6. • Idea: move from one global IPv4 address per broadband customer to one IPv4 address shared by many broadband customers.

5. Network gets increasinglycomplex to operate. Plan B: Overlay of RFC1918Home Provisioning Internet ISP Carrier grade NAT Carrier grade NAT Net 10 Net 10 CMTS CMTS IPv6 Private v4 address Home Gateway NAT v4->v4 Private v4 address Home Gateway NAT v4->v4 Private v4 address Home Gateway NAT v4->v4 IPv4 Legacy Device Dual Stack Device 192.168/16 192.168/16 192.168/16 IPv6-only Device

6. Simplifies network operation. Provide an upgrade path to IPv6. Plan C: 464 NAT Internet ISP Carrier grade NAT Carrier grade NAT Internet CMTS CMTS IPv6 IPv6 provisionedHome Gateway IPv6 provisionedHome Gateway IPv6 provisionedHome Gateway IPv4 Legacy Device Dual Stack Device 192.168/16 192.168/16 192.168/16 IPv6-only Device

7. Implication of IPv6 Home Networking on Routing Scalability

8. IPv4 Social Contract • 1 global, dynamic IPv4 address per household shared among several devices • External IPv4 Address may change over time • NAT in the home gateway • Stability of internal IPv4 addresses is not dependant on what happens on the WAN • Devices are not visible from the outside

9. New IPv4 Social Contract • 1 global, dynamic IPv4 address shared among several household. • External IPv4 Address may change over time • NAT in the carrier network • Devices are not visible from the outside in IPv4 • Stability of internal IPv4 addresses is not dependant on what happens on the WAN • IPv6 available in the home

10. IPv6 Social Contract • Similar to IPv4 • Dynamic /64 (or more) • Stateful firewall in home gateway • Internal devices are not visible from the outside • No stable addresses • Need to renumber the home network when ISP changes attachment point • New & Improved • Stable /56 • Devices don’t have to renumber if ISP changes attachment point • Devices can be contacted from the outside using their stable IPv6 address • “shared” management of home gateway security model

11. Scaling the Routing System to Accommodate “Stable” IPv6 Prefixes • Stable: immune to regular changes in ISP topology, not to customer relocating. Routers in the (local) access network need to exchange all routes for all (local) customers 200k – 1 million in small/medium routers Exchange Customer Routes Split