1. Agenda
1. QUIZ
2. HOMEWORK
3. ATM
4. SONET/SDH/OTN
5. NETWORK DEVICES

2. (Ethernet Frame) Bits: 7 1 2/6 2/6 2 0 - 1500 0 - 46 4 To From
/ /
To From
addr addr
Pre-
amble
Data
Pad Check
sum
Start of
frame
delimiter
Length of
data field

3. (IP Header) 32 bits Version IHL Type of service Total lengthM F
Identification
Fragment offset
Time to live
Protocol
Header checksum
Source address
Destination address
Options (0 or more words)

4. (TCP Header) 32 bits Source port Destination port Sequence number
Acknowledgement number
TCP
header
length U R G A C K P S H R S T S Y N F I N
Window size
Checksum
Urgent pointer
Options (0 or more 32 bit words)
Data (optional)

5. Homework
19-1, 19-3, 19-6, 19-73, 19-82
20-1, 20-6, 20-13, 20-55
21-2, 21-51

6. Chapter 19
ATM

7. Multiplexing Using Different Packet Sizes
Figure 19-1
Multiplexing Using Different Packet Sizes
We have packets as large as 65,545 bytes sharing systems with
systems with packets having fewer than 200 bytes
What does the size of X do to A?

8. Multiplexing Using Cells
Figure 19-2
Multiplexing Using Cells
Cell network overcomes delay problems by using the cell as the
basic unit of data exchange, so X becomes X, Y & Z (smaller
fixed size blocks).

9. Figure 19-3
ATM Multiplexing
Note: Multiplexer output is sequential like token ring
Call it TDM or CDM?

10. Architecture of an ATM Network Showing User-
Figure 19-4
Architecture of an ATM Network Showing User-
Network & Network-Network Interface Points
What is the difference?

11. Transmission Path, Virtual Paths, and Virtual Circuits
Figure 19-5
Transmission Path, Virtual Paths, and Virtual
Circuits
Virtual Circuit means
Part or all of the paths are the same?
All cells follow the same route for a message or transmission?

12. Example of VPs and VCs Figure 19-6
8 end points using 4 virtual circuits

13. Virtual Path & Virtual Circuit Connection Identifiers
Figure 19-7
Virtual Path & Virtual Circuit
Connection Identifiers

14. Virtual Connection Identifiers
Figure 19-8
Virtual Connection Identifiers
in UNIs and NNIs
Why does NNI have more Virtual Path Indicator bits?

15. Figure 19-9
An ATM Cell
(One Size Fits All)

16. Figure 19-10
SVC
Setup
Same as X.25
& Frame Relay?
What about PVC?

17. Routing with a VP Switch
Figure 19-11
Routing with a VP Switch
Virtual Path Switch uses only Virtual path identifiers (like IP table?)

18. A Conceptual View of a VP Switch
Figure 19-12
A Conceptual View of a VP Switch
Virtual path identifiers change but virtual circuit identifiers don’t.

19. Routing with a VPC Switch (Combining VP & VC Switches)
Figure 19-13
Routing with a VPC Switch
(Combining VP & VC Switches)

20. A Conceptual View of a VPC Switch
Figure 19-14
A Conceptual View of a VPC Switch
What does this add to the VP switch? It uses VCIs too & not just VPIs.

21. Figure 19-15
Crossbar Switch

22. Knockout Switch Uses distributors & queues to direct cells
Figure 19-16
Knockout Switch
Uses distributors &
queues to direct cells
to different queues at the
output.
With n inputs & n outputs
you need n2 crosspoints.
So?

23. A Banyan Switch Multi stage with microswitches at each stage
Figure 19-17
A Banyan Switch
Multi stage with microswitches at each stage
For n inputs & n outputs you have log2(n) stages & n/2 microswitches
What probability of cell collision?

24. Batcher-Banyan Switch
Figure 19-19
Batcher-Banyan Switch
Buffer?
Overcomes Banyan by sorting incoming cells by their final destination

25. Figure 19-20
ATM Layers

26. ATM Layers in End-Point Devices and Switches
Figure 19-21
ATM Layers in End-Point Devices and Switches
Note: Switches use only two bottom layers

27. Data Types & Sub-layer Functions
Constant bit rate (CBR) has no delays & good for real time
Variable bit rate (VBR) at some burst level
Connection oriented packet data like X.25 & TCP
Connectionless packet data like most IP
Sub-layers
Convergence divides the bit stream into 47 byte segments
SAR adds a one byte header so 48 bytes goes to ATM layer

28. Figure 19-22
AAL Types

29. AAL1 Note: CSI used for signaling while SC for error & flow control
Figure 19-23
AAL1
Note: CSI used for signaling while SC for error & flow control

30. AAL2 Note: IT says where in message & LI points to how much padding
Figure 19-24
AAL2
Note: IT says where in message & LI points to how much padding

31. Figure 19-25
AAL3/4

32. Figure 19-26
AAL5
What happened to all the control complexity?

33. ATM Layer Routing, traffic management, switching & multiplexing
Figure 19-27
ATM Layer
Routing, traffic management, switching & multiplexing

34. Figure 19-28
ATM Header

35. Payload Type (PT) Fields
Figure 19-29
Payload Type (PT) Fields

36. Figure 19-30
Service Classes

37. Service Classes and Capacity of Network
Figure 19-31
Service Classes and Capacity of Network

38. QoS Sustained Cell Rate Cell Loss Ratio Peak Cell Rate
Figure 19-32
QoS
Sustained Cell Rate
Peak Cell Rate
Minimum Cell Rate
Cell Variation Delay
Cell Loss Ratio
Cell Transfer Delay
Cell Delay Variation
Cell Error Rate
How about a term paper on the value of each of these?

39. Figure 19-33
ATM WAN
Are these routers or gateways?

40. Ethernet Switch and ATM Switch
Figure 19-34
Ethernet Switch and ATM Switch
Connectionless vs. connection oriententation
Physical address vs. virtual connection identifiers
Broadcast vs.

41. Local Area Network Emulation (LANE) Approach
Figure 19-35
Local Area Network Emulation (LANE) Approach
What do Broadcast/Unknown server & LANE clients add? Connectionless Service

42. Lane Clients (LEC), Lane Servers (LES), and
Broadcast/Unknown Server (BUS)

43. Chapter 20
SONET/SDH

44. Synchronous Transport Signal Multiplexers
Figure 20-1
The SONET System Using
Synchronous Transport Signal Multiplexers

45. An Example of a SONET Network
Figure 20-2
An Example of a SONET Network
Regenerators regenerate & change some header information. So?

46. SONET Layers PL: end-to-end, LL: mux-to-mux, SL: neighbors; like OSI?
Figure 20-3
SONET Layers
PL: end-to-end, LL: mux-to-mux, SL: neighbors; like OSI?

47. Device-Layer Relationship in SONET
Figure 20-4
Device-Layer Relationship in SONET

48. Data Encapsulation in SONET
Figure 20-5
Data Encapsulation in SONET
Note the pretty overhead additions.

49. Figure 20-6
STS-1 Frame
Is this structure or throughput?

50. STS-1 Frame Overhead (showing Synchronous Payload Envelope)
Figure 20-7
STS-1 Frame Overhead
(showing Synchronous
Payload Envelope)

51. STS-1 Frame Section Overhead
Figure 20-8
STS-1 Frame Section Overhead

52. STS-1 Frame Line Overhead
Figure 20-9
STS-1 Frame Line Overhead

53. Figure 20-10
Payload Pointers
ID location of payload when it is someplace other than the beginning

54. STS-1 Frame Path Overhead
Figure 20-11
STS-1 Frame Path Overhead

55. Figure 20-12
Virtual Tributaries
VTs for multiple sources?

56. Figure 20-13
VT Types

57. Figure 20-14
STS-n

58. Figure 20-15
STS Multiplexing

59. Figure 20-16
ATM in an STS-3 Envelope
With STS-3 ( Mbps) entire payload can be used for cell transport
260 octets can carry close to 5 cells (5 X 53 = 265 bytes)
Recall STS-1 is Mbps

60. Broadband’s Future: Optical Networking
Background:
Over 100 standards are currently on the drafting table
Networkers should no longer need to purchase monthly or yearly for one-time capacity
Networks may not be structurally sound:
Ethernet/IP mentality eschews complex networks
SONET-voice & security worlds argue for multi-layered networks with all the complexity and protection that implies.

61. Broadband’s Future: Optical Networking
Same old conflict:
The SONET successor is the Optical Transport Network (OTN) which could work across an Automatic Switched Optical Network (ASON)
The IP-centric approach uses Generalized Multiprotocol Label Switching (GMPLS)

62. Broadband’s Future: Optical Networking
SONET’s disadvantages:
Bandwidth efficiency is a problem at higher capacities. More overhead is required.
It’s a single wavelength solution (so far)
It’s ignorant of the underlying infrastructure
Providers are left to manage two layers:
The SONET network with its point to point Wavelength Division Multiplex network
The layer-2 or layer-3 networks that might be transported across the SONET network.
SONET’s advantage: It’s circuit switched.

63. Optical fiber/OTN (WDM)
IP to WDM Choices IP
IEEE LLC
IEEE LLC
PPP
AAL 5
RPR
MAC
Ethernet MAC
HDLC
ATM
POS
RPR
PHY
10GigE
LAN PHY
10GigE
WAN PHY
GigE
PHY
GFP
SONET/SDH
Interface for OTN, G.709
WDM, WWDM, DWDM
Optical fiber/OTN (WDM)

64. IP to WDM Choices Acronyms: RPR = Resilient Packet Ring, IEEE 802.17
HDLC = High-level Data Link Control
POS = Packet over SONET/SDH
GFP = Generic Framing Procedure (ANSI T1 X1 driven standard)
OTN = Optical Transport Network
WDM = Wavelength Division Multiplexing
WWDM = Wide WDM
DWDM = Dense WDM

65. Optical Networking Approaches
Overlay Model: Maintaining two discrete networks: A layer-1 optical network and a client network. Users access the underlying optical network through User Network Interfaces (UNIs). Devices in the optical network rely on Network-to-Network Interfaces (NNIs).
Peer-to-peer Model: A single network, equipment at the networks edge decides how bandwidth is allocated at the network core.

66. Overlay Approach: ITU Plan
Divide connections into three components (like SONET):
The path (the logical connection between stations) called optical channels, to provide end-to-end networking.
The line (the underlying physical link) called optical multiplex sections, to underpin the channels; but these are expanded to have multiple wavelengths when SONET has one.
The sections (the individual copper or fiber spans that terminate at the amplifiers or regenerators) called the optical transmission section to define the physical interface that details the optical parameters such as frequency (wavelength), power level, signal-to-noise ratio, etc.
Include a SONET-like hierarchy called the Optical Transport Hierarchy

67. Networking and Internetworking Devices
Chapter 21
Networking
and
Internetworking
Devices

68. Figure 21-1
Connecting Devices

69. Connecting Devices and the OSI Model
Figure 21-2
Connecting Devices and the OSI Model

70. A Repeater in the OSI Model
Figure 21-3
A Repeater in the OSI Model

71. A Bridge in the OSI Model
Figure 21-6
A Bridge in the OSI Model

72. A Router in the OSI Model
Figure 21-10
A Router in the OSI Model

73. A Gateway in the OSI Model
Figure 21-12
A Gateway in the OSI Model

74. Figure 21-16
Switch

75. Figure 21-17
Example of an Internet

76. The Concept of Distance
Figure 21-18
The Concept of Distance
Vector Routing

77. Concept of Link State Routing
Figure 21-24
Concept of Link State Routing

78. Figure 21-27
Flooding of A’s LSP