The document summarizes key aspects of IP interconnection and peering relationships between internet service providers (ISPs). It describes how the internet is comprised of over 30,000 semi-autonomous ISPs that interconnect in a decentralized manner. Peering relationships allow ISPs to exchange traffic between a predefined portion of their networks, while transit relationships provide connectivity to all destinations in one provider's routing table. The benefits of peering for ISPs and content providers include reduced costs, improved performance, and greater network control compared to purchasing full transit.

1. IP
Interconnec*on
Panel
IP
possibili*es
-­‐
2013
steve
ulrich
(sulrich@cisco.com)
/
@sulrich

2. Internet
structure
National
ISP
National
ISP
National
ISP
Transit
ISP
Transit
ISP
Regional
ISP
Regional
ISP
Regional
ISP
Regional
ISP
Local
ISP
Local
ISP
Local
ISP
Local
ISP
Local
ISP
• the
Internet
is
an
interconnec*on
of
~30,000
(semi-­‐)autonomous
service
providers
• there
is
no
central
coordina*on
for
the
management
of
interconnec*ons,
services,
and
tariffs
• Internet
peering
ecosystem
includes
many
policies
/
many
services
/
one
Internet
• unordered
subset
of
interconnects
• driven
by
business
requirements
underpinned
by
performance
• non-­‐disclosure
and
bi-­‐lateral
agreements
• peering
is
now
considered
a
corporate
asset
and
legal
concern
Local
ISP
Local
ISP
Local
ISP
Local
ISP
Local
ISP
Transit
ISP
Transit
ISP
National
ISP
National
ISP
National
ISP
Regional
ISP
Regional
ISP
Regional
ISP
Regional
ISP
reality
tradi*onal
assump*on

3. transit
-­‐
defini*on
• transit
is
the
business
rela*onship
where
one
ISP
provides
reach-­‐ability
to
all
des*na*ons
in
its
rou*ng
table
to
its
customers
• transit
provides
connec*vity
to
a
superset
of
all
des*na*ons
Client Net
Client Net
Client Net
Client Net
ISP C
ISP B
ISP D
Client Net
Client Net
Client Net
Client Net
ISP A Can Reach All
Destinations via Transit
Provider ISP D
Peers
Peers
ISP A Transit

4. peering
-­‐
defini*on
• peering
is
the
business
rela*onship
where
ISPs
provide
to
each
other
reach-­‐ability
to
each
predefined
por*ons
of
their
rou*ng
table
• peering
provides
connec*vity
to
a
subset
of
a
provider’s
customer
des*na*ons
Peers
Peers
Transit
Client Net
Client Net
Client Net
Client Net
ISP C
ISP B
ISP A
Client Net
Access to ISP B Prefixes Only
ISP D
Client Net
Client Net
Client Net

5. 5
©
2009
Cisco
Systems,
Inc.
All
rights
reserved.
Cisco
Confiden*al
20091103
OPASTCO
Peering
-­‐
sulrich
tradi*onal
Internet
peering
model
• *er
1
providers
have
access
to
the
en*re
Internet
(region)
rou*ng
table
solely
through
peering
rela*onships
• *er
2
providers
must
buy
some
transit
from
*er
1
providers
• content
providers
buy
transit
(primarily
from
*er
1)
to
provide
content
Tier 1 Tier 1
Tier 2 Tier 2
Enterprise Content Enterprise

6. 6
©
2009
Cisco
Systems,
Inc.
All
rights
reserved.
Cisco
Confiden*al
20091103
OPASTCO
Peering
-­‐
sulrich
Internet
peering
evolu*on
• *er
1
providers
have
access
to
the
en*re
Internet
(region)
rou*ng
table
solely
through
peering
rela*onships
• *er
2
providers
must
buy
some
transit
from
*er
1
providers
• content
providers
peer
with
access
networks
providing
content
directly
onto
the
broadband
networks
IOC / RLEC
content
provider Enterprise
Tier 1 Tier 1
Tier 2 Tier 2
CDN

7. peering
ra*onale
• commonly
es*mated,
10
-­‐
20%
of
traffic
can
be
peered
away
• even
under
conges*on,
capacity
can
be
upgraded
and
managed
more
effec*vely
• improve
applica*on
performance,
reduc*on
in
latency
– improvement
in
throughput
• CDNs
as
content
providers
• peering
at
NAPs
or
with
ISPs
improves
burstability
– backup
for
on-­‐net
servers
• marke*ng
-­‐
CDNs
tout
the
number
of
interconnec*ons
they
have
to
their
customers
7
for the ISP for content providers
• reduce
transit
ISP
service
costs
• upgrades
require
less
planning
and
costs
• greater
control
over
rou*ng
and
traffic
load
balancing
common to both

8. Internet
peering
interconnec*on
ISP #1
ISP #6
ISP #5
ISP #4
ISP #3
ISP #2
switched ethernet
ISP #2ISP #1
ethernet
public / shared peering
private peering
• peering
between
equivalent
sizes
of
service
providers
(e.g.
*er
2
to
*er
2)
shared
cost
private
interconnec*on,
equal
traffic
flows
“no
cost
peering”
• peering
across
exchange
points
if
convenient,
of
mutual
benefit,
technically
feasible
• fee
based
peering
unequal
traffic
flows,
“market
posi*on”

9. addi*onal/local
resources
• h[p://peeringdb.com
find
a
peering
loca*on
near
you!
• MICEMN
– h[p://micemn.net/
– here
in
minneapolis,
mn
– less
than
2
miles
from
where
you’re
standing/siang
MICEMN
par*cipants
Airstream
Communica*ons
AITech
Akamai
Technologies
Arvig
Berbee
Informa*on
Networks
Corpora*on
Coopera*ve
Network
Services,
LLC
Enven*s
Telecom
Hurricane
Electric
Integra
Telecom
ipHouse
MDU
Ethernet
Solu*ons
Minnesota
VoIP
Paul
Bunyan
Communica*ons
Savage
Communica*ons
Inc.
Spiralight
Network
LLC
TDS
Telecom
US
Internet
VISI
Wikstrom
Telephone
Company,
Inc.

10. THANK
YOU
steve
ulrich
(sulrich@cisco.com)
/
@sulrich