Self-Test Vol. 1 Unit 4 Flashcards
Into what two groups can you divide the OSI model?
Application and Transport
What is the responsibility of the Data Transport layers of the OSI model?
Define how data travels, the physical media, through internetwork devices, to the destination computer, and to the application on the destination machine.
This layer divides into two sub layers: LLC and MAC.
Data Link
This layer typically includes multiplexing, virtual circuit management, and error checking and recovery.
Transport
This layer defines the electrical, mechanical, procedural, and functional specifications for network communications.
Physical
A hub operates at this layer.
Physical
Switches and bridges operate at this level.
Data Link
This layer provides a variety of coding and conversion functions that are applied to application layer data.
Presentation
A router operates at this layer.
Network
This layer establishes, manages, and terminates communication sessions.
Session
At this layer, common data compression and encryption schemes are used.
Presentation
Describe the DISN.
A telecommunications network that provides the exchange of information in an interoperable and global space, divided by security demands, transmission requirements, and geographic needs of targeted end-user customers.
What unclassified IP data service provides internet connectivity and supports e-mail and web services?
SBU IP Data
List the key features of VoSIP.
Providing an interface between the IP telephony and the circuit-switched net, a full range of supplemental user features, a seperate IP address space, firewalls at each VoSIP site and access control lists on all routers to ensure only permitted traffic flows, secure voice communications up to and including Secret.
What service uses a number of different satellite services to provide warfighters with worldwide access and GIG connectivity for diversity, redundancy and availability?
Commercial Satellite Service
Transport protocols have two classifications based on the way data transports, name the two classifications.
Connection and connectionless oriented
What must occur between ends before transfer of information in a connection-oriented environment?
Connection between sender and recipient happens prior.
Define buffering.
Network devices temporarily stores bursts of excess data in memory until the receiving machine utilizes it.
The easiest way to break down the many protocols of the TCP/IP suite is according to where they operate within the OSI model. Each protocol in this stack operates at one of what four layers?
Data link, network, transport, or application layer.
The protocols at the Data Link layer define the access method for the media, the architecture, and interface with the Physical layer of the network. What standards are these protocols based on?
Project 802 standards.
What are the four most important TCP/IP protocols that function within the network layer?
IP, ARP, RARP, ICMP
What are the fields belonging to a TCP segment?
Source port, destination port, sequence number, acknowledge number, TCP header length, reserved, flags, sliding-window size, checksum, urgent pointer, options, padding, data.
In the context of TCP/IP, what is a packet also known as?
IP datagram
What are the two main parts of an IPv4 address?
The network number and the host number.
Who assigns network numbers?
IANA
The first bit (0) identifies the address class and, together with the next seven bits, identifies the network number.
Class A
There are about 2,097,152 networks, with 254 host on each network.
Class C
Reserved for multicase addressing.
Class D
What class address is 233.1.1.254?
Class C
What class address is 9.10.254.111?
Class A
The first four bits (1111) identify the address class.
Class E
What class address is 154.224.32.3
Class B
There are about 16,384 networks, with 65,534 hosts on each network.
Class B
What is the reserved IPv4 address for loop back?
127.0.0.1
What is the reserved IPv4 address for limited broadcast?
255.255.255.255
What is a subnet mask?
A mechanism that allows a network device to devide an IP address into a network and host number.
What are the two methods of subnet masking?
Classful and classless
What are some benefits to subnetting?
Ease administration, improve network performance, and security.
How long is an IPv6 address?
16 octets long or 128 bits
How is an IPv6 address expressed?
16-byte fields
What are the two ways to shorten the expression of an IPv6 address?
Leading zero compression and zero compression
What is a unicast address?
Identifies a single interface. A packet sent to a unicast address delivers to the interface identified by that address.
What is a multicast address?
Identifies a group of interfaces belonging to different nodes. Multicast packets send to all interfaces identified by that address.
What is an Anycast address?
Identifies a set of interfaces, but the packets deliver to and accept by the closest interface.
What are the three types of unicast address?
Link-local, site-local, and global
What is the IPv6 loop back address?
0:0:0:0:0:0:0:1 or ::1
What does a TCP/IP client use to request a particular service?
Port numbers
What is the range of well-known port numbers?
0 to 1023
What is the default port assignment for TELNET?
23
What is the default port assignment for credit card transactions on e-commerce sites?
443
