Telecom Chapter 2 - Network Standards

Connection-Oriented Protocol

(TCP - Transmission Control Protocol only protocol that is this) Two sides first agree that they will communicate and formally stop communicating at the end. Reliable!!

OSI-RM Standards Architecture

7. Application 6. Presentation 5. Session 4. Transportation 3. Network 2. Data Link 1. Physical (created by ITU-T and ISO)

Application

Broad function is interoperability of application programs

Data Link and Physical

Broad function is transmission across a single network

Transport and Internet

Broad function is transmission across an internet

Data Link Layer Standards

Govern frame organization and switch operation. Govern the transmission of frames across a single switched, wireless, or point-to-point network.

Application Layer Standards

Govern how two applications work with each other, even if they are from different vendors.

Internet Layer Standards

Govern the transmission of packets across the Internet—typically by sending them through several routers along the route. Govern packet organization and routing.

Physical Layer Standards

Govern transmission between adjacent devices connected by a transmission medium, regardless of who the two vendors are.

Octet/Byte

Group of 8 bits

TCP 80

HTTP (WWW)

Network Standards

Rules of operation that specify how two hardware or software processes work together by exchanging messages

Headers

SYN segments have...

TCP/IP Standards Architecture (created by IETF)

4. Application 3. Transport 2. Internet 1. Subnet Access Protocol

Hybrid TCP/IP-OSI Standards Architecture

5. Application 4. Transport 3. Internet 2. Data Link 1. Physical

Header

A message always has a ________. (holds Host IP Address and Destination IP Address)

Various standards architectures

Application maintained from ________.

Transport Layer Standards

Aspects of end-to-end communication between two end hosts not handled by the internet layer. Includes application message fragmentation and reliability.

Application

At what layer is encoding done?

Data link

At what layer will you find standards for MAC (EUI-48) addresses?

Internet

At what layer will you find standards for packets?

OSI (Reference Model of Open Systems Interconnection) and TCP/IP (Transmission Control Protocol / Internet Protocol)

From which standards architectures do organizations typically take their standards?

ISO and ITU-T

Create a variety of network standards, especially for physical and data link processes. (who created OSI-RM)

IETF (Internet Engineering Task Force)

Created standards for the Internet, especially internet processes, transport processes, and Internet supervisory standards (DNS, etc.)

OSI-RM standards architecture

Data Link and Physical (or just subnet access protocol in TCP/IP Arch) maintained from _________.

2

During a connection opening, how many TCP segments will the side that initiates the connection send?

802.3

Ethernet

HTTP Request and Response Message

Host A sends: HTTP request message Host B sends: TCP ACK segment and HTTP response message Host A sends: ACK If HTTP request doesn't arrive to host B, host A just sends again. {Error} All in Transport Layer; in TCP all segments are ACKed, except for pure ACKs.

HTTP Request and Response Message with Error

Host A sends: HTTP request message {ERROR} Host A sends: HTTP request message b/c no ACK so it retransmits Host B sends: TCP ACK segment and HTTP response message Host A sends: ACK If HTTP request doesn't arrive to host B, host A just sends again. {Error} All in Transport Layer; in TCP all segments are ACKed, except for pure ACKs.

Four-Step Close

Host A sends: TCP FIN segment Host B sends: ACK and more data Host A sends: ACK Host B sends: FIN Host A sends: ACK All in Transport Layer; in TCP all segments are ACKed, except for pure ACKs.

Three-Step Opening

Host A sends: TCP SYN segment Host B sends: TCP SYN/ACK segment Host A sends: TCP ACK segment All in Transport Layer; in TCP all segments are ACKed, except for pure ACKs.

Socket

IP Address:Port Number

NOT transmit an ACK, NAC, or RSND segment

If a destination host does not receive a segment, it will ________.

Discards the packet

If the destination internet process detects an error, it ________.

5

If two hosts are connected by five networks, how many frames will there be when one host sends a packet to the other host?

6

If two hosts are connected by five point-to-point networks, how physical links will there be when one host sends a packet to the other host?

Twice as many alternatives

If you add one bit to an alternatives field, you can have ________.

Interoperability

Network standards provide ________.

Connectionless Protocol

No need to have live connection before transmitting. (HTTP, IP, UDP, PPP, and Ethernet) Therefore unreliable.

Reduces cost

Not making all protocols reliable ________.

TCP

ONLY reliable protocol, because it's the only connection-oriented (not connectionless) protocol

Applications

On a server, well-known port numbers indicate ________.

Ephemeral Port Number

On client computers; Only used for a single set of interactions between the client and a server; Randomly generated.

PDITA

Physical, DLink, Internet, Transmission, Application (Hybrid TCP/IP-OSI Standards Architecture)

Please Do Not Throw Sausage Pizza Away

Physical, DLink, Network, Transport, Session, Presentation, Application (ITU-T and ISO created [OSI-RM])

SMTP (Simple Mail Transfer Protocol) Application

Port 25

FTP (File Transfer Protocol) Application

Ports 20 and 21

OSI-RM standards architecture

Reference Model of Open Systems Interconnection, created by ISO and ITU-T. Numbered 1-7

Application

Standard that mostly comes from Various Standards Architectures

ISO (Int'l Organization for Standardization) & ITU-T (Int'l Telecommunications Union - Telecommunications Standards Sector)

Standards organizations/agencies that created OSI-RM Standards Architecture

Transport and Internet

Standards that come from TCP/IP (IETF)

Data Link and Physical

Standards that mostly come from OSI (ITU-T and ISO)

True

TCP is a connection-oriented protocol. T/F

True

The internet process checks for errors. T/F

OSI-RM Standards Architecture

The standards architecture of ISO and ITU-T

False

There is always a data field in a message. T/F

7

Transmitting "Oh, My!" without the quotes in ASCII requires ________ octets.

TCP/IP standards architecture

Transport and Internet/Network maintained from ___________.

Data Link and Physical

Which layer(s) governs transmission through a single network?

Internet Engineering Task Force (IETF)

Which of the following is a standards agency for the Internet?

Internet Engineering Task Force (IETF)

Which standards agency is especially important for Internet supervisory processes?

ISO (Int'l Organization for Standardization) & ITU-T (Int'l Telecommunications Union - Telecommunications Standards Sector)

Which standards agency is especially important for data link processes?

Internet Engineering Task Force (IETF)

Which standards agency is especially important for internet processes?

ITU-T

Which standards agency is especially important for physical transmission processes?

Internet Engineering Task Force (IETF)

Which standards agency is especially important for transport processes?

None of these

Which standards layer governs e-mail?

Standard Agencies

Who standards are developed by, ex: ISO, ITU-T

TCP/IP (Transmission Control Protocol / Internet Protocol)

_____ is the architecture while ______ separated are the standards within the architecture.

OSI-RM standards architecture

open systems interconnectivity reference model. Numbered 1-7

Standards architectures

specify everything needed for two different programs on two different hosts on a single network to interoperate.