DOC

Point-to-all-points

By Roy Hughes,2014-11-10 06:10
13 views 0
Point-to-all-points

1

2

Multicast Services over

Internet

3

    Outlines:

Multicast in Current Internet

     Introduction

     Broadcast

     Multicast

     IGMP

     MBONE

     4

# Introduction

; Unicast

    - point-to-point transmission

; Broadcast

    - Point-to-all-points

; Multicast

    - Point-to-group-points

    - Members of a group have the same network

    address

    - Advantages:

     Reduce bandwidth utilization

     Reduce network address assignment

     5

Unicast

    ; Network address is defined at OSI IP layer ; IP address

    - four bytes length

    - The value range of each byte is 0 -255

    - NIC (Network Information Center is responsible for

    IP address assignment

    - IP Classes:

    Class Address Range

    CLASS A 0.0.0.0 ~ 127.255.255.255

    (00.00.00.00 ~ 7f.ff.ff.ff )

    CLASS B 128.0.0.0 ~ 191.255.255.255

    (80.00.00.00 ~ bf.ff.ff.ff )

    CLASS C 192.0.0.0 ~ 223.255.255.255

    (c0.00.00.00 ~ df.ff.ff.ff )

    CLASS D 224.0.0.0 ~ 239.255.255.255

    (e0.00.00.00 ~ ef.ff.ff.ff )

    CLASS E Reserved for future

    - Class D is used for Multicast

     6

    ; IP address format: netid | subnetid | hostid

    - the subnetid bits and hostid bits are specified by

    subnet mask

    ; Subnet mask is a 32-bit value containing one bits for

    the network ID and subnet Id and zero bits for the host

    ID.

; MAC address of Ethernet

    - Six bytes length

    - The value range of each byte is 0-255

     7

# Broadcast

    ; A host wants to send a frame to every other hosts on

    the network

    ; Ethernet broadcast address is ff:ff:ff:ff:ff:ff

; Forms of IP Broadcast -- four forms:

    1. Limited Broadcast:

    - Broadcasting only appears on the local network

    - Limited broadcast address is 255.255.255.255

    2. Net-directed Broadcast:

    - Broadcasting appears on the specified network

    - The net-directed broadcast address has a host ID

    of all one bits

    - For example, a class A net-directed broadcast

    address is netid.255.255.255, where netid is the

    class A network ID

    3. Subnet-directed Broadcast:

     8

    - Broadcasting appears on a specified sub-network

    of a network

    - The subnet-directed broadcast address has a host

    ID of all one bits but a specific subnet ID

    - For example, if a router receives a datagram

    destined for 128.1.2.255, this is a subnet-directed

    broadcast if the class B network 128.1 has a

    subnet mask of 255.255.255.0

    4. All-subnets-directed Broadcast:

    - Broadcasting appears on all sub-networks of a

    network

    - Both the subnet ID and the host ID are all one

    bits

    - For example, if the destination's subnet mask is

    255.255.255.0, then the IP address 128.1.255.255

    is an all-subnets-directed broadcast.

    - If the network is not subnetted, then this is a

    net-directed broadcast

     9

# Multicast

    ; A host sends frames to multiple destinations, which

    belong to a specific "group" and may be spanned on

    multiple LANs

    ; The set of hosts listening to a particular IP multicast

    address is call a "group"

; A group is formed by members

    ; RFC1054 (Request For Comments 1054) defines the

    "Host Extensions for IP Multicasting"

    ; Broadcast and multicast only apply to UDP at

    available systems

     10

Report this document

For any questions or suggestions please email
cust-service@docsford.com