L11. What is broadcast, unicast, multicast, anycast and flooding? Flashcards
What are broadcast, unicast, multicast, anycast, and flooding?
Communication paradigms used in computer networking to deliver data packets to one or multiple destinations.
What is broadcast?
Broadcast communication involves sending a message from one sender to all recipients within a network domain. In a broadcast transmission, the sender does not specify the individual recipients; instead, the message is intended for all devices within the network segment.
What are the characteristics of broadcasting?
One-to-All Communication: The sender transmits a single message that is received by all devices within the broadcast domain.
Limited Scope: Broadcast messages are typically confined to the local network segment and are not forwarded beyond routers or network boundaries.
Addressing: Broadcast messages are addressed using special broadcast addresses, such as the IP address 255.255.255.255 in IPv4 or the broadcast MAC address in Ethernet.
What is unicast?
Unicast communication involves sending a message from one sender to a specific recipient or destination address. In a unicast transmission, the sender explicitly identifies the intended recipient, and the message is delivered only to that recipient.
What are the characteristics of unicast?
One-to-One Communication: Each unicast transmission involves a single sender and a single recipient.
Point-to-Point Delivery: Unicast messages are delivered directly from the sender to the recipient, without involving other devices in the network.
Addressing: Unicast messages are addressed using the unique identifier (e.g., IP address or MAC address) of the intended recipient.
What is multicast?
Multicast communication involves sending a message from one sender to multiple specific recipients or a group of recipients. In a multicast transmission, the sender identifies a multicast group, and the message is delivered to all members of that group.
What are the characteristics of multicast?
One-to-Many Communication: Each multicast transmission involves a single sender and multiple recipients who are part of the multicast group.
Efficient Bandwidth Usage: Multicast messages are sent only once by the sender and are replicated by network devices to reach multiple recipients, reducing network bandwidth usage.
Addressing: Multicast messages are addressed using a multicast group address, which identifies the group of recipients interested in receiving the message.
What is anycast?
Anycast communication involves sending a message from one sender to the nearest or best-suited destination among multiple possible recipients. In an anycast transmission, the sender sends the message to a single destination address, and the network routes it to the closest member of the anycast group.
What are the characteristics of anycast?
One-to-One-of-Many Communication: Anycast transmissions involve a single sender and multiple recipients, but the message is delivered to only one recipient, typically the nearest or most optimal one.
Dynamic Routing: Anycast routing relies on network protocols to determine the optimal destination for each transmission based on factors such as network topology and routing metrics.
Addressing: Anycast messages are addressed using the same destination address as unicast messages, but the network infrastructure determines which member of the anycast group receives the message.
What is flooding?
Flooding is a simple and straightforward communication method where a sender broadcasts a message to all connected network devices without regard to destination addresses. In a flooding transmission, the sender replicates the message and sends it to all adjacent devices in the network.
What are the characteristics of flooding?
One-to-All Communication: Flooding involves broadcasting a message to all devices within the network, similar to broadcast communication.
Redundant Delivery: Since flooding does not rely on addressing, the message may be received by multiple devices, leading to redundant or duplicate delivery.
Usage in Routing and Discovery: Flooding is commonly used in network protocols for tasks such as routing table updates and network discovery, where broadcasting messages to all devices helps ensure widespread dissemination of information.
Name use cases for broadcast
Address Resolution Protocol (ARP): In Ethernet networks, ARP is used to resolve IP addresses to MAC addresses. When a device needs to determine the MAC address corresponding to a given IP address, it broadcasts an ARP request to all devices on the local network segment. The device with the matching IP address responds with its MAC address.
DHCP Discovery: During the Dynamic Host Configuration Protocol (DHCP) process, a client broadcasts a DHCP discover message to request an IP address assignment from a DHCP server. The DHCP server responds to the broadcast with a DHCP offer, initiating the IP address configuration process.
Name use cases for unicast
Web Browsing: When a user accesses a website using a web browser, the browser sends HTTP requests to the specific IP address of the web server hosting the website. These requests are unicast transmissions, as they are directed to a single destination—the web server—identified by its IP address.
Email Communication: Sending an email from one user to another involves unicast communication. The email client or mail server sends the email message directly to the recipient’s email server, using the recipient’s email address as the destination identifier.
Name use cases for multicast
Video Streaming: Multicast is commonly used for distributing live video streams, such as online video conferences or live television broadcasts. In a multicast video streaming scenario, the video source sends a single video stream to a multicast group address, and multiple recipients, such as viewers or conference participants, join the multicast group to receive the stream.
Software Updates: Distributing software updates or patches to a large number of devices within a network can be efficiently accomplished using multicast. The update server sends the update package to a multicast group address, and devices interested in receiving the update join the multicast group to download the update.
Name use cases for anycast
Content Delivery Networks (CDNs): CDNs use anycast to deliver content to users from the nearest or most optimal server location. When a user requests content from a CDN, the request is directed to the nearest CDN server using anycast routing, ensuring faster response times and reduced network latency.
Domain Name System (DNS): Anycast is employed in DNS infrastructure to improve the availability and performance of DNS resolution services. DNS servers are deployed in multiple geographic locations, and DNS queries are routed to the nearest DNS server using anycast routing, reducing DNS resolution time and enhancing reliability.
