Transcript PowerPoint Presentation - ANCP

Framework & Requirements
for an Access Node Control Mechanism in
Broadband Multi-Service Networks
ANCP WG
IETF 71 – Philadelphia
draft-ietf-ancp-framework-05.txt
Presenter: Stefaan De Cnodder
Main Updates in v05
• Multicast use case reworked out per IETF discussion
– Conditional Access
– Admission Control
– Accounting
• Time and volume accounting
– Spontaneous Admission Response
• Updated corresponding Access Node and NAS
requirements
Use Case – Multicast
• Conditional Access
–
–
–
–
White List: AN accepts locally
Black List: AN rejects locally
Grey List: AN queries the NAS for a decision
Algorithm when Join message is received:
• If multiple entries in one or more lists match, then entry with “most
specific match” is selected
• If there are multiple “most specific match” entries:
– Black list has precedence over Grey and White list
– Grey list has precedence over White list
• If no match, then discard Join message
– “catch-all” entries allowed
• E.g reject all messages: <S=*, G=*> in black list
Use Case – Multicast
• Admission Control
– Option 1: AN processes IGMP and queries the NAS for CAC
decision
• Admission Request / Admission Response
– Option 2: AN does not process IGMP; NAS performs CAC
decision and instructs the AN
• All subscriber IGMP signaling is terminated on the NAS
– Option 3: Policy Server queries the AN
• Either directly, or indirectly via the NAS
• Not addressed in this document
Use Case – Multicast
• Disabling Admission Control
– Could be done by adding a “catch-all statement” for unknown
streams
• <S=*,G=*> in white list
• Any more specific match continues to take precedence over this entry,
so this works only for “unknown streams”
• Should be marked as best-effort
– Example use: accept Internet multicast streams that are offered as
best effort traffic
• no need for CAC; Internet multicast will use remaining available best
effort bandwidth
Use Case – Multicast
• Multicast Admission Control & white lists
– When using white lists for guaranteed QoS content, CAC is
required on the Access Node
• If not, grey list needs to be used instead
• CAC on the Access Node requires some means to provision
bandwidth information on the Access Node
– not addressed in this document
– CAC for combined white/black/grey lists are not addressed in this
document
Use Case – Multicast
• Accounting
– Option 1: AN keeps track of when replication starts or stops,
generates the time and/or volume accounting information and
sends it to a central accounting system (no ANCP required)
– Option 2: AN keeps track of when replication starts or stops and
reports this to the NAS
• Basic accounting: Information Report when replication starts/ends
• Detailed accounting: Basic + traffic volume replicated
Use Case – Multicast
• Spontaneous Admission Response
– NAS can dynamically stop the replication of a multicast flow
• NAS sends “Admission Response” to AN to terminate replication
– NAS can control multicast replication when IGMP messages are
not processed in the access network
• NAS receives no Admission Request messages
Next steps
• The authors propose to send draft-ietf-ancp-framework-05
to Last Call
Backup
History
• Jan 2006: draft-ooghe-l2cp-framework-00.txt submitted
for L2CP BOF
• May 2006:
draft-ooghe-ancp-framework-00.txt
• November 2006: draft-ietf-ancp-framework-00.txt
• March 2007:
draft-ietf-ancp-framework-01.txt
• July 2007:
draft-ietf-ancp-framework-02.txt
• October 2007:
draft-ietf-ancp-framework-03.txt
• November 2007: draft-ietf-ancp-framework-04.txt
• February 2008: draft-ietf-ancp-framework-05.txt
Reference Architecture
+--------+
| Policy |
| Server |
+--------+
|
|
+-----+
+-----+
+--------+
+-----+
+----------+
| CPE |---| HGW |---|
|
|
|
|
|
+-----+
+-----+
| Access |
+---------+
|
|
| Regional |
| Node |---| Aggreg. |---| NAS |---| Network |
+-----+
+-----+
|
|
| Node
|
|
|
|
|
| CPE |---| HGW |---|
|
+---------+
|
|
|
|
+-----+
+-----+
+--------+
+-----+
+----------+
Information Report / Admission Request
-------------------------->
Admission Response / Control Request
<-------------------------Control Response
-------------------------->
Access Node Control Mechanism
<------------------------->
PPP, DHCP, IP
<---------><------------------------------------->
Terminology
• Line Rate
– total data rate including overhead
• Net Data Rate
– portion of the total data rate that can be used to transmit user information
(e.g. ATM cells or Ethernet frames). It excludes overhead that pertains to
the physical transmission mechanism (e.g. trellis coding in case of DSL)
• Control Channel
– a bidirectional IP communication interface between the controller function
(in the NAS) and the reporting/enforcement function (in the AN)
• Access Node Control Adjacency
– relationship between an Access Node and a NAS for the purpose of
exchanging ANCP messages. The adjacency may either be up or down,
depending on the result of the Access Node Control Adjacency protocol
operation.
• Multicast flow
– multicast Any Source Multicast group or multicast Source Specific
Multicast (S,G) channel
Use Case - Dynamic Access Loop
Attributes
• Communicating Access Loop attributes
– Beneficial since the Access Loop rate may change overtime
• NAS gains knowledge about the topology of the access
network (e.g. for QoS scheduling)
Use Case - Access Loop Configuration
• Change Access Loop parameters (e.g. rate) from the NAS
– Avoids cross-organization business-to-business interactions
– Allows to centralize Subscriber-related service data in e.g. a policy
server
• The best way to change Access Loop parameters is by
using profiles
– pre-configured on the Access Node using EMS
• Mechanism could be used for additional parameters (e.g.
QoS)
Use Case – Remote Connectivity Test
• NAS can use ANCP to initiate an Access Loop test
between Access Node and HGW
– Allows mixed ATM/Ethernet environment
– Supports multiple Access Loop technologies (e.g. ATM/ADSL,
Ethernet/VDSL)
• Preserve existing operational functionality
Access Node requirements
•
General Architecture
– Partitioning
– Redundant controllers
•
•
•
Control Channel Attributes
Capability Negotiation Failure
Adjacency Status Reporting
– Adjacency protocol
•
Identification
– In line with TR-101 (e.g. Access-Node-Identifier atm slot/port:vpi.vci)
– The AN MUST use the same ACI format for identifying the AN and access port in
ANCP, PPPoE and DHCP messages
•
•
•
Multicast
Message Handling
Parameter Control
– Damping
– Bundling
•
Security
Network Access Server requirements
•
General Architecture
–
–
–
–
•
•
•
•
Partitioning
Shaping based on Dynamic Access Loop Attributes
Access Loop Configuration
Remote Connectivity Test
Control Channel Attributes
Capability Negotiation Failure
Adjacency Status Reporting
Identification
– In line with TR-101 (e.g. Access-Node-Identifier atm slot/port:vpi.vci)
•
•
•
Multicast
Message Handling
Wholesale Model
– Communicate Access Loop Attributes to an LNS
•
Security
Conditional Access - algorithm
<S,G> matches
an entry in one
of the lists
Yes
Find the “best
match” entry
Yes
Apply decision
associated with list
<S,G>
“best match”
applies to one
list
No
No
Apply decision
associated with list
+ precedence rule
- Black takes priority over Grey / White
- Grey takes priority over White
Reject request