1. Structure of the Internet
Fred Baker

2. Campus Networks (LANs)
Today’s Internet
Campus Networks (LANs)
The optical internet backbone
Gigabit to terabit links
UoSAT-12
Internet
in Airlines
Access networks
xDSL, cable modem, ISDN, asynchronous dial
20,000 instantaneous sessions per GBPS backbone bandwidth

3. Nearby Traceroute
traceroute to ( ), 30 hops max, 40 byte packets
 1  sjcm-dc-gw1.cisco.com ( )  0.86 ms  0.49 ms  0.54 ms
 2  sjce-sbb1-gw1.cisco.com ( )  0.54 ms  0.48 ms  0.35 ms
 3  sjck-rbb-gw2.cisco.com ( )  0.39 ms  0.39 ms  0.48 ms
 4  sj-wall-1.cisco.com ( )  0.59 ms  0.35 ms  0.51 ms
 5  sjce-dirty-gw1.cisco.com ( )  2.01 ms  0.74 ms  0.66 ms
 6  barrnet-gw.cisco.com ( )  1.88 ms  0.67 ms  0.60 ms
 7  p3-3.paloalto-cr2.bbnplanet.net ( )  3.13 ms  1.74 ms  1.48 ms
 8  p1-0-0.paloalto-cr9.bbnplanet.net ( )  2.94 ms  1.73 ms  2.94 ms
 9  f0-0.paloalto-cr13.bbnplanet.net ( )  5.07 ms  2.22 ms  1.86 ms
10  sunet-gateway.stanford.edu ( )  7.36 ms  4.42 ms  1.81 ms

4. Nearby Traceroute
traceroute to arachne.berkeley.edu ( ), 30 hops max, 40 byte packets
 1  sjcm-dc-gw1.cisco.com ( )  0.85 ms  0.57 ms  0.60 ms
 2  sjce-sbb1-gw1.cisco.com ( )  0.50 ms  0.38 ms  0.40 ms
 3  sjce-rbb-gw1.cisco.com ( )  0.56 ms  0.42 ms  0.44 ms
 4  sj-wall-1.cisco.com ( )  0.46 ms  0.47 ms  0.37 ms
 5  sjce-dirty-gw1.cisco.com ( )  0.69 ms  0.86 ms  1.11 ms
 6  barrnet-gw.cisco.com ( )  0.63 ms  2.33 ms  0.60 ms
 7  p3-3.paloalto-cr2.bbnplanet.net ( )  2.04 ms  1.39 ms  1.36 ms
 8  p7-1.paloalto-nbr2.bbnplanet.net ( )  1.53 ms  1.53 ms  1.43 ms
 9  p1-0.paix-bi1.bbnplanet.net ( )  1.76 ms  1.84 ms  2.19 ms
10  p0-0.xpaix21-qwest.bbnplanet.net ( )  1.94 ms  1.77 ms  1.83 ms
11  ( )  3.24 ms  3.80 ms  3.50 ms
12  ( )  3.91 ms  3.34 ms  2.70 ms
13  ( )  4.14 ms  2.61 ms  3.02 ms
14  QSV-M10-C2.GE.calren2.net ( )  4.40 ms  2.76 ms  2.55 ms
15  atm1-1-0dot1.inr-new-666-doecev.Berkeley.EDU ( )  7.08 ms  6.25 ms  5.70 ms
16  vlan196.inr-202-doecev.Berkeley.EDU ( )  9.39 ms  ms  8.58 ms
17  vlan210.inr-203-eva.Berkeley.EDU ( )  ms  ms  ms
18  arachne.Berkeley.EDU ( )  ms  8.01 ms  8.05 ms

5. International Traceroute
traceroute to bells.cs.ucl.ac.uk ( ), 30 hops max, 40 byte packets
 1  sjcm-dc-gw1.cisco.com ( )  0.83 ms  0.67 ms  0.85 ms
 2  sjce-sbb1-gw1.cisco.com ( )  0.47 ms  1.43 ms  0.41 ms
 3  sjce-rbb-gw1.cisco.com ( )  0.44 ms  0.37 ms  0.34 ms
 4  sj-wall-1.cisco.com ( )  0.39 ms  0.37 ms  0.35 ms
 5  sjce-dirty-gw1.cisco.com ( )  1.65 ms  0.68 ms  0.61 ms
 6  sjc-k-isp-gw1.cisco.com ( )  1.94 ms  1.53 ms  0.62 ms
 7  POS2-3.GW5.SJC2.ALTER.NET ( )  2.28 ms  3.43 ms  2.35 ms
 8  161.ATM5-0.XR2.SJC2.ALTER.NET ( )  2.62 ms  1.41 ms  1.22 ms
 9  0.so XL2.SJC2.ALTER.NET ( )  3.11 ms  2.27 ms  1.57 ms
10  0.so TL2.SAC1.ALTER.NET ( )  5.77 ms  4.80 ms  4.77 ms
11  0.so IL2.NYC9.ALTER.NET ( )  ms  ms  ms
12  so IR2.NYC12.ALTER.NET ( )  ms  ms  ms
13  so TR1.LND9.Alter.Net ( )  ms  ms  ms
14  so XR2.LND9.Alter.Net ( )  ms  ms  ms
15  pos2-0.gw1.lnd9.alter.net ( )  ms  ms  ms
16  ukerna-gw.pipex.net ( )  ms  ms  ms
17  po15-0.lond-scr.ja.net ( )  ms  ms  ms
18  po0-0.london-bar1.ja.net ( )  ms  ms  ms
19  ( )  ms  ms  ms
20  ucl.lmn.net.uk ( )  ms  ms  ms
21  ( )  ms  ms  ms
22  ( )  ms  ms  ms
23  cisco.cs.ucl.ac.uk ( )  ms  ms  ms
24  bells.cs.ucl.ac.uk ( )  ms  ms  ms

6. Autonomous System Interconnection
Access Networks
AS:
“A routing system using a single protocol and under common administration”
AS in center
High connectivity
AS at edge
Low connectivity
Major ISPs

7. Routing by contract BGP Routing is essentially routing by contract
Goal is not to achieve a good route, but a usable one for which money changes hands
Broad contract categories:
“Peering”
“Transit”

8. Peering Contracts Contract among equals
“I will advertise my customers to you”
To get full routes, have to peer with every major network
Relatively expensive to service
Packets that enter my network will always be delivered in my network
Peering contracts may produce little or no revenue, as they are essentially a trade for access to peer’s customers

9. Transit contracts Contract between provider and customer
“I will advertise the ability to get anywhere”
Often some combination of default and individual routes
“Full” routes can be gotten from any major provider, but may be inefficient routes.
Relatively inexpensive to service
Packets often handed to next hop network quickly,
Packets only sometimes spend time in my network
However, transit contracts produce revenue

10. Components of agreements
Contracts always under NDA
Therefore little direct knowledge outside key players
Key components
Routes advertised
Ability to advertise routes
Assigned Prefix (Enterprise)
Multihoming
Applied bandwidth
Load threshold at which bandwidth is increased
Delay and loss rates acceptable
Uptime requirements
Cost of service
Flat Rate or Usage Pricing

11. Queuing Theory and QoS Mean queue depth, and therefore delay
Nominal Delay and Jitter
Greater Delay, Jitter, and Loss
Link utilization

12. Key issues is supporting SLA
Fundamentally, the issue is
Bandwidth and
Reachability

13. Key problems in global routing
Asymmetric Routes resulting from differences in policy
Convergence issues resulting from
Differences in policy
Algorithms and parameters in routing

14. Structure of the Internet
Fred Baker