Broadband Forum
Focus: IPv6 Home Network
David Miles
david.miles@alcatel-lucent.com
Disclaimer
The views in this presentation do not
represent the opinion of the Broadband Forum
or its members.
All document are Work In Progress.
2 | Presentation Title | Month 2007
1
What is the
Broadband Forum?
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The Broadband Forum Vision
Develop the full potential of broadband around the world.
Mission
The Broadband Forum is a worldwide organization committed to rapidly creating
specifications for communication service providers and vendors that Accelerate the development and deployment of broadband networks,
Foster successful interoperability,
Manage and deliver advanced IP services to the customer.
http://www.broadband-forum.org/about/mission.php
Forum History
The Broadband Forum is a global consortium of nearly 200 leading industry players
covering telecommunications, equipment, computing, networking and service provider
companies.
Established in 1994, originally as the ADSL Forum and later the DSL Forum, the
Broadband Forum continues its drive for a global mass market for broadband, to
deliver the benefits of this technology to end users around the world over existing
copper telephone wire infrastructures.
http://www.broadband-forum.org/about/forumhistory.php
4 | Presentation Title | Month 2007
2
IPv6 for Consumer
Deployment Options
5 | Presentation Title | Month 2007
Native IPv6
IPv6
Home
Network
IPv6
Gateway
IPv6
Internet
Softwires from Client in the Home Network
IPv6
Home
Network
Softwire Client
L2TP Tunnel
DSL Router
(Existing)
IPv4
Internet
IPv6
Internet
Softwire
Concentrator
Native IPv6 using L2TP
IPv6
Home
Network
L2TP
PPPoA
IPv6
Gateway
LAC
IPv6
Internet
IPv6 LNS
Host Access using PPPoE
L2TP
PPPoE
IPv6
Internet
Bridge
LAC
IPv6 LNS
Host Access using Softwires
L2TP
Tunnel
PPPoE
IPv4 Router
IPv4
Internet
IPv6
Internet
Softwire
Concentrator
3
IPv6 for Consumer
Broadband
WT-177 and WT-187
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Routing Home Network
Subnet A
Internet
Subnet B
IPv4
NAT Function
UDP
TCP
TCP
UDP
IPv4
IPv4
Ethernet
Ethernet
IPoE IWF
Ethernet
RFC 2684
ATM
DSL
IPv4
802.1ad
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
IPv6
Routing
IPv6
Ethernet
Ethernet
RFC 2684
ATM
DSL
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IPoE IWF
Ethernet
IPv6
802.1ad
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
Routed Gateway with PPPoE WAN (1)
Subnet A
Subnet B
Routed Gateway
BNG
RADIUS
PPPoE
PADI – PADO – PADR - PADS
PPP LCP ConfReq
ConfReq: MRU, Magic Number
PPP LCP ConfReq
ConfReq: MRU, Magic Number, Auth=PAP
PPP LCP ConfAck
ConfReq: MRU, Magic Number, Auth=PAP
PPP LCP ConfAck
ConfReq: MRU, Magic Number
PAP Authenticate-Request
Username (Peer-ID)+ Password
RADIUS Access-Request
User-Name, Password, Service-Name VSA
Service-Type=Framed, Framed-Protocol=PPP
RADIUS Access-Accept
Delegated-IPv6-Prefix, IPv6-DNS,
(IPv6-Address/Framed-IPv6-Pool)
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Routed Gateway with PPPoE WAN (2)
Subnet A
Subnet B
Routed Gateway
BNG
RADIUS
PAP Authenticate-Ack
IPv6CP ConfReq
Interface-Id= 64-bit Interface ID/Client
PPP
Phase
IPv6CP ConfAck
Interface-Id= 64-bit Interface ID/Client
IPv6CP ConfReq
Interface-Id= 64-bit Interface ID/BNG
IPv6CP ConfAck
Interface-Id= 64-bit Interface ID/Client
RADIUS Accounting-Request
Start, User-Name, Service-Name VSA
Service-Type=Framed, Framed-Protocol=PPP
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Routed Gateway with PPPoE WAN (3)
Subnet A
Subnet B
Routed Gateway
BNG
Multicast Router Advertisement
Numbered: M=1,O=0, No PIO
Un-numbered: M=0, O=1, No PIO
DHCPv6 SOLICIT
IA_PD-Option, (IA_NA-Option), DNS-Servers Option
DHCPv6 ADVERTISE
DHCPv6
Phase
IA_PD-Option + Prefix, (IA_NA)
DHCPv6 REQUEST
IA_PD-Option, (IA_NA-Option), DNS-Servers Option
DHCPv6 REPLY
IA_PD-Option + Prefix, (IA_NA)
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RADIUS
Routed Gateway with Ethernet WAN (1)
Subnet A
Subnet B
Routed Gateway
BNG
RADIUS
Multicast Router Advertisement
Numbered: M=1,O=0, No PIO
Un-numbered: M=0, O=1, No PIO
DHCPv6 SOLICIT
IA_PD-Option, (IA_NA-Option), DNS-Servers Option
RADIUS Access-Request
User-Name, Password, Service-Name VSA
Service-Type=Framed
DHCPv6
Phase
RADIUS Access-Accept
Delegated-IPv6-Prefix, IPv6-DNS,
(IPv6-Address/Framed-IPv6-Pool)
DHCPv6 ADVERTISE
IA_PD-Option + Prefix, (IA_NA)
DHCPv6 REQUEST
IA_PD-Option, (IA_NA-Option), DNS-Servers Option
DHCPv6 REPLY
IA_PD-Option + Prefix, (IA_NA)
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Bridged Home with PPPoE Host
Internet
IPv4
IPv4
PPPoE
Bridge
Ethernet
Ethernet
RFC 2684
ATM
DSL
802.1ad
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
IPv6
IPv6
PPPoE
Bridge
Ethernet
RFC 2684
ATM
DSL
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Ethernet
802.1ad
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
Bridged Home with PPPoE Host (1)
PPPoE
Client
Bridge
BNG
RADIUS
PPPoE
PADI – PADO – PADR - PADS
PPP LCP ConfReq
ConfReq: MRU, Magic Number
PPP LCP ConfReq
ConfReq: MRU, Magic Number, Auth=PAP
PPP LCP ConfAck
ConfReq: MRU, Magic Number, Auth=PAP
PPP LCP ConfAck
ConfReq: MRU, Magic Number
PAP Authenticate-Request
Username (Peer-ID)+ Password
RADIUS Access-Request
User-Name, Password, Service-Name VSA
Service-Type=Framed, Framed-Protocol=PPP
RADIUS Access-Accept
IPv6-DNS, Framed-IPv6-Prefix
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Bridged Home with PPPoE Host (2)
PPPoE
Client
Bridge
BNG
RADIUS
PAP Authenticate-Ack
IPv6CP ConfReq
Interface-Id= 64-bit Interface ID/Client
IPv6CP ConfAck
Interface-Id= 64-bit Interface ID/Client
PPP
Phase
IPv6CP ConfReq
Interface-Id= 64-bit Interface ID/BNG
IPv6CP ConfAck
Interface-Id= 64-bit Interface ID/Client
RADIUS Accounting-Request
Start, User-Name, Service-Name VSA
Service-Type=Framed, Framed-Protocol=PPP
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Bridged Home with PPPoE Host (3)
PPPoE
Client
Bridge
BNG
RADIUS
Anti-Spoofing
Installed
Multicast Router Advertisement
M=0, O=1
Prefix Information Option: from Framed-IPv6-Prefix
DHCPv6 INFORMATION-REQUEST
DNS-Servers Option
DHCPv6 REPLY
DNS-Servers Option
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Optional
DHCPv6
Stateless
Phase
4
Prefix Size
Broadband Subscribers
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IPv4 and IPv6 Routing Gateways
Internet
IPv4
NAT Function
UDP
TCP
TCP
UDP
IPv4
IPv4
Ethernet
Ethernet
IPoE IWF
Ethernet
RFC 2684
ATM
DSL
IPv4
802.1ad
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
IPv6
Routing
IPv6
Ethernet
Ethernet
RFC 2684
ATM
DSL
22 | Presentation Title | Month 2007
IPoE IWF
Ethernet
IPv6
802.1ad
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
IPv4 and IPv6 Routing Gateways
Internet
IPv4
NAT Function
UDP
TCP
TCP
UDP
IPv4
IPv4
Ethernet
Ethernet
RFC 2684
ATM
DSL
IPv6
Routing
IPv6
Ethernet
Ethernet
RFC 2684
ATM
DSL
23 | Presentation Title | Month 2007
Network Address Translation
Customer-selected addresses on LAN
IPoE IWF
Ethernet
IPv4
802.1ad
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
IPv6 Routed
IPoE IWF addresses on the LAN IPv6
Provider-assigned
802.1ad
Ethernet
802.1ad
Ethernet
Ethernet
802.3 PHY
802.3 PHY
IPv6 Prefix Delegation
•Allows the routing gateway to receive a range of IPv6 addresses (a prefix) that are
valid for that subscriber. The gateway must manage the assignment of individual
addresses to hosts outside the scope of Prefix Delegation.
Routing
Gateway
BNG
DHCPv6 Solicit
IA_PD Option
DHCPv6 Advertise
IA_PD: Prefix Option: <prefix>
DHCPv6 Request
IA_PD: Prefix Option: <prefix>
DHCPv6 Reply
IA_PD: Prefix Option: <prefix>
24 | Presentation Title | Month 2007
Contents of the Prefix Delegation Option
0
16
32
Option IA_PD
option-length
IAID
Timer 1
Timer 2
Option IAPREFIX
option-length
Preferred Lifetime
Valid Lifetime
prefix-length
IPv6 Prefix
IPv6 Prefix
25 | Presentation Title | Month 2007
Contents of the Prefix Delegation Option
0
16
Option IA_PD
32
option-length
IAID
Contact the delegating router at this time to extend
Contact _any_ delegating router at this time to extend
Option IAPREFIX
option-length
Preferred Lifetime of addresses derived from this prefix
Valid Lifetime of addresses derived from this prefix
prefix-length
IPv6 Prefix
IPv6 Prefix
26 | Presentation Title | Month 2007
How Small?
If Stateless Address Auto-Configuration (SLAAC) is to
be supported, the prefix-length of any IPv6 link
must be exactly 64-bits
::/64
RFC 4862:
“If the sum of the prefix length [in the PIO] and the
interface identifier length is not equal to 128 bits, the Prefix
Information option MUST be ignored”
RFC 2464: IPv6 over Ethernet
The Interface Identifier is 64-bits and is based on the EUI-64
format.
27 | Presentation Title | Month 2007
How Big?
Single Subnet
Internet
Subnet A
Two Subnets
Subnet A
Internet
Subnet B
Cascading Routers
Subnet A
Subnet B
28 | Presentation Title | Month 2007
Subnet C
Internet
The views
http://www.apnic.net/policy/ipv6-guidelines.html
An LIR can assign a /64 to /48 to an end site customer network based on their
requirements. The following guidelines may be useful:
/64 where it is known that only one subnet is required.
/56 for small sites where it is expected only a few subnets will be required within the next
two years. Subscribers can receive a /56 when connecting through on-demand or always-on
connections such as small office and home office enterprises.
/48 for larger sites, or if an end site is expected to grow into a large network.
An LIR must submit a second opinion request to APNIC if it plans to assign more than a /48
to a single end site
Assignments for networks equal to or greater than /48 must be registered.
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What is the impact?
Using a prefix longer than a ::/56 does not affect
your allocation. HD-Ratio is calculated against ::/56
prefixes.
The use of a shorter prefix does not increase the
number of routes or FIB entries in Service Provider
infrastructure.
In the minimum /32 LIR allocation, there are:
16,777,216 ::/56
6,183,533 ::/56 at HD-Ratio 0.94
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How many subnets is enough?
With cascading routers we must support at least two
subnets.
The closest nibble is a /60, with 16 subnets.
WT-187 and WT-177 Requirement:
R-xx: A minimum delegation of a ::/60 to a Routing
Gateway.
R-xx: A recommended delegation of a ::/56 to a
Routing Gateway.
31 | Presentation Title | Month 2007
5
IPv6 Addressing
Importance of Persistent Addresses
32 | Presentation Title | Month 2007
Impact of Valid & Preferred Lifetimes
0:00:00
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
Host links can come up before the broadband connection.
Impact of Valid & Preferred Lifetimes
0:01:00
DHCPv6 Prefix Delegation
T1: 30 min T2: 48 min
IA_PD: 2001:db8:1::/64
Preferred: 3600 Valid: 43200
Router Advertisement
PIO: 2001:db8:1::/64
Preferred: 3600 Valid: 43200
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,600
43,200
Preferred
DHCPv6-PD options used in Router Advertisements.
Impact of Valid & Preferred Lifetimes
0:01:30
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,570
43,170
Preferred
Lifetimes are tracked by the Host and decremented.
Impact of Valid & Preferred Lifetimes
0:01:35
Router Advertisement
PIO: 2001:db8:1::/64
Preferred: 3565 Valid: 43165
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,565
43,165
Preferred
And the RG also tracks lifetimes so that any RA
are accurate.
Impact of Valid & Preferred Lifetimes
0:01:40
Router Advertisement
ROUTER LIFETIME: 0
PIO: 2001:db8:1::/64
Preferred: 3560 Valid: 43160
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,560
43,160
Preferred
If the Broadband Link goes down, set Router Lifetime
to zero (0) so that the RG is not used as default router.
Impact of Valid & Preferred Lifetimes
0:02:40
Router Advertisement
ROUTER LIFETIME: 0
PIO: 2001:db8:1::/64
Preferred: 3500 Valid: 43100
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,500
43,100
Preferred
Prefixes are still valid even when link is down.
RA continue to be sent.
Impact of Valid & Preferred Lifetimes
1:02:40
Address
Valid Lifetime
Preferred
Lifetime
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
0
39,500
Deprecated
Impact of Valid & Preferred Lifetimes
1:05:00
DHCPv6 Prefix Delegation
T1: 30 min T2: 48 min
IA_PD: 2001:db8:1::/64
Preferred: 3600 Valid: 43200
Router Advertisement
PIO: 2001:db8:1::/64
Preferred: 3600 Valid: 43200
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,600
43,200
Preferred
Whenever DHCPv6-PD provides the RG new lifetimes
these are reflected in the RA
Impact of Changing Prefixes
1:06:00
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,540
43,140
Preferred
Impact of Changing Prefixes
1:07:00
DHCPv6 Prefix Delegation
T1: 30 min T2: 48 min
IA_PD: 2001:db8:2::/64
Preferred: 3600 Valid: 43200
Router Advertisement
PIO: 2001:db8:2::/64
Preferred: 3600 Valid: 43200
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
3,540
43,140
Preferred
2001:db8:2::aaaa
3,600
43,200
Preferred
Source Address Selection is NOT deterministic, however the
Broadband Network Gateway is only expecting traffic
sourced from 2001:db8:2::/64
Better Behaviour
1:07:00
DHCPv6 Prefix Delegation
Router Advertisement
T1: 30 min T2: 48 min
IA_PD: 2001:db8:2::/64
Preferred: 3600 Valid: 43200
PIO: 2001:db8:1::/64
On-Link
PREFERRED:
0 Valid: 43080
Autonomous, On-Link
PIO: 2001:db8:2::/64
Preferred: 3600 Valid: 43200
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
0
43,080
Deprecated
2001:db8:2::aaaa
3,600
43,200
Preferred
Instead, let us Deprecate the old addresses.
We cannot invalidate because of DoS-protection rules.
Better Behaviour
1:07:30
Router Advertisement
PIO: 2001:db8:2::/64
Preferred: 3540 Valid: 43140
Autonomous, On-Link
Address
Preferred Life
Valid Life
State
fe80::aaaa
Infinite
Infinite
Preferred
2001:db8:1::aaaa
0
43,020
Deprecated
2001:db8:2::aaaa
3,540
43,140
Preferred
Source Address Selection will now prefer the new
address space.
6
IPv6 Addressing
Minimising Prefix Changes
45 | Presentation Title | Month 2007
Address Hierarchy @ BNG – Day 2
2001:db8:0:0::/56
2001:db8:0:100::/56
Route table
-----------------------------------------------------------2001:db8::/39
aggregate
lo0
2001:db8:0:0::/56
2001:db8:0:100::/56
...
subscriber
subscriber
eth1
eth1
2001:db8:0:200::/56
2001:db8:0:300::/56
2001:d8b::/39
2001:db8:0:400::/56
2001:db8:0:500::/56
2001:db8:200:0::/56
Route table
-----------------------------------------------------------2001:db8:200:/39
aggregate
lo0
2001:db8:200:0::/56
2001:db8:200:100::/56
...
subscriber
subscriber
eth1
eth1
2001:db8:200:100::/56
2001:db8:200:200::/56
46 | Presentation Title | Month 2007
2001:d8b:200:/39
Address Hierarchy @ DSLAM – Day 1
2001:db8:0:0::/56
Route table
-----------------------------------------------------------2001:db8::/46
aggregate
lo0
2001:db8:4::/46
aggregate
lo0
2001:db8:8::/46
aggregate
lo0
2001:db8:0:100::/56
2001:db8:0:200::/56
2001:d8b::/46
2001:db8:4:0::/56
2001:db8:4:100::/56
2001:db8:4:200::/56
2001:d8b:4::/46
2001:db8:8:0::/56
2001:db8:8:100::/56
2001:db8:8:200::/56
2001:d8b:8::/46
47 | Presentation Title | Month 2007
2001:db8:0:0::/56
2001:db8:0:100::/56
...
subscriber
subscriber
eth1
eth1
Address Hierarchy @ DSLAM – Day 2
Route table
-----------------------------------------------------------2001:db8::/46
aggregate
lo0
2001:db8:4::/46
aggregate
lo0
2001:db8:0:0::/56
2001:db8:0:100::/56
2001:db8:0:0::/56
2001:db8:0:100::/56
...
2001:db8:0:200::/56
subscriber
subscriber
eth1
eth1
2001:d8b::/46
2001:db8:4:0::/56
2001:db8:4:100::/56
2001:db8:4:200::/56
2001:d8b:4::/46
2001:db8:8:0::/56
2001:db8:8:100::/56
2001:db8:8:200::/56
2001:d8b:8::/46
48 | Presentation Title | Month 2007
Route table
-----------------------------------------------------------2001:db8:8:/46
aggregate
lo0
2001:db8:8:0::/56
2001:db8:8:100::/56
...
subscriber
subscriber
eth1
eth1
Address Hierarchy
Prefix Delegation
 The BNG should aggregate subscriber /56 prefixes into
supernets within the service provider domain. The aim is
to reduce the size of the service provider routing table.
 Logically group prefixes by the largest logical device
(switch, DSLAM, etc) that is persistent regardless of normal
network rearrangement.
Recommend: Each access node should be represented by its own unique prefix-pool
when DHCPv6 PD is in use
49 | Presentation Title | Month 2007
www.alcatel-lucent.com
Thank You
50 | Presentation Title | Month 2007