A Straw-Man Pricing Model Addressing the Multicast Deployment Problem

1
A Straw-Man Pricing Model Addressing the
Multicast Deployment Problem

• Version 0.1
• January, 2003
• Bill Woodcock
• Packet Clearing House
• Zhi-Li Zhang
• University of Minnesota Digital Technology Center

2
The Problem

• The technological problems of multicast routing
  are relatively well in-hand, and
• There are users and applications which would
  benefit from being able to use a multicast routed
  infrastructure, and
• Multicast unquestionably provides advantages of
  economy and efficiency, but

3
The Problem

• The billing model which evolved in the unicast
  environment is too inequitable when applied in a
  multicast environment to provide ISPs with any
  incentive.

4
The Unicast Economic Model

• ISPs sell access to their combined mix of network
  edges (customers, peers, and transit providers)
  to their customers.

Peer
Customer
Transit
Customer
5
The Unicast Economic Model

• The sum of the customers use of the ISPs
  network

Peer
Customer
Transit
Customer
6
The Unicast Economic Model

• The sum of the customers use of the ISPs
  network
• can be measured at the point at which its
  aggregated, facing the customer.

Peer
Customer
Transit
Customer
7
The Unicast Economic Model

• The sum of the customers use of the ISPs
  network
• can be measured at the point at which its
  aggregated, facing the customer.
• Other expenses can be amortized proportion-ately
  across all customers.

Peer
Customer
Transit
Customer
8
How Multicast Breaks This Model

• Multicast traffic is multiplied within the ISPs
  network

Peer
Customer
Transit
Customer
9
How Multicast Breaks This Model

• Multicast traffic is multiplied within the ISPs
  network
• such that the sum of the edge utilization

Peer
Customer
Transit
Customer
10
How Multicast Breaks This Model

• Multicast traffic is multiplied within the ISPs
  network
• such that the sum of the edge utilization
• may be far greater than whats observed at the
  point at which it enters from the customer.

Peer
Customer
Transit
Customer
11
But Thats Just a Billing Problem

• In terms of efficient use of the network,
  multicast is far preferable

Peer
Customer
Transit
Customer
12
But Thats Just a Billing Problem

• In terms of efficient use of the network,
  multicast is far preferable
• to filling the backbone with redundant unicast

Peer
Customer
Transit
Customer
13
But Thats Just a Billing Problem

• And for the recipients ISP, multicast is an
  unqualified benefit

Customer
Customer
Customer
14
But Thats Just a Billing Problem

• And for the recipients ISP, multicast is an
  unqualified benefit
• since the sum of the exit points

Customer
Customer
Customer
15
But Thats Just a Billing Problem

• And for the recipients ISP, multicast is an
  unqualified benefit
• since the sum of the exit points
• is greater than the bandwidth required to bring
  it into the network.

Customer
Customer
Customer
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So How Do We Characterize the Inequity?

• As a starting point, customers who send multicast
  are already paying for a connection, and paying
  for unicast utilization.
• So we need to identify the difference between
  what the customer currently pays for, and what
  the ISP has to provide in a multicast environment.

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So How Do We Characterize the Inequity?

• In this example, the customer is paying for one
  unit of service

1
Source
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So How Do We Characterize the Inequity?

• In this example, the customer is paying for one
  unit of service
• but receiving four

1
1
1
1
1
Source
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So How Do We Characterize the Inequity?

• In this example, the customer is paying for one
  unit of service
• but receiving four
• for a difference of three.

1
1
1
1
4-13
1
Source
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The Difference is Transitive

• If the sources transit providers also split the
  traffic

1
1
1
1
1
1
1
1
1
Source
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The Difference is Transitive

• If the sources transit providers also split the
  traffic
• each of the three ASes receives revenue from one
  customer circuit

1
1
1
1
1
1
1
1
X-1Y
X-1Y
1
Source
X-1Y
22
The Difference is Transitive

• If the sources transit providers also split the
  traffic
• each of the three ASes receives revenue from one
  customer circuit
• and replicates it to two destinations

1
1
1
1
1
1
1
1
2-11
2-11
1
Source
2-11
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The Difference is Transitive

• If the sources transit providers also split the
  traffic
• each of the three ASes receives revenue from one
  customer circuit
• and replicates it to two destinations
• so we have the same overall replication factor of
  three.

1
1
1
1
1
1
1
1
2-11
2-11
1
Source
2-11
1113
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• Bill Woodcock
• woody_at_pch.net
• Zhi-Li Zhang
• zhzhang_at_cs.umn.edu
• www.pch.net/resources/papers/multicast-billing