Class Terminology¶
We will refer to common terms that define networking equipment and the behavior of protocols in the network. These terms help define the context of our descriptions.
- data¶
The part of a bit stream that a particular protocol is intending to transmit, also payload.
- mac address¶
Network interface address
- preamble¶
Sequence of one and zero bits to help synchronize with a packet clock
- FSD¶
Frame sequence delimiter - sequence of bits in a specific pattern to indicate the start of an ethernet packet
- FCS¶
Frame check sequence - verifies the integrity of a packet
- EtherType¶
The type identification for the payload contents of an ethernet packet
- layer 1¶
Connectivity graph of network physical media
- on-the-wire¶
Typically refers to the physical signaling protocol that defines how a higher layer (higher than L1) protocol’s data may be formatted for transmission over the physical network medium
- network interfaces¶
The reference to the hardware and software components that enable a device’s physical and logical connectivity
- protocol¶
The functional operation and associated formatting of packets that define a data exchange in the network
- protocol behavior¶
Specification for the logical operation of a protocol with events and responses for the participating network devices
- protocol format¶
Types of packets and the packet fields that constitute what byte stream patterns are expected for a protocol
- packet¶
The particular data unit for each protocol with pre-defined fields including the payload
- encapsulation¶
A protocol packet may be encapsulated in another protocol packet’s payload field
- frame¶
The protocol data unit for Ethernet is generally referred to as a frame. The frame has physical layer fields that help with the electrical signaling to work for asynchronous transmission of data between Ethernet interfaces and ports
- Ethernet¶
The dominant layer 2 protocol in current networks where hosts have a network interface card with a MAC address which is the addressing scheme for Ethernet protocol
- bridge¶
A layer 2 device, an Ethernet MAC learning bridge for this class context, that does not change a packet header other than the VLAN ID field. A switch may refer to this definition of bridge but usually has layer 3 function as well
- bridge port¶
The physical interface of a bridge where hosts and other network devices are connected to
- host¶
An end point compute element in the network where user applications may run
- topology¶
A collection of network devices, hosts, and links that define the connections at a specified layer. For example, all physical wiring between bridges and hosts would refer to a layer 1 topology for a network
- network graph¶
The graphical representation of network devices and functions at vertices and network links as edges
- vertex¶
The network devices and functions constitute the vertices or the nodes in our network graphs
- edge¶
The network links are represented by the edges in our network graphs
- link¶
The edges in our network graph are network links
- router¶
A layer 3 device that forwards packets based on layer 3 packet header fields
- Internet Protocol¶
Internet Protocol (IP) is a layer 3 protocol that provides the data transmission between networks addressed as IP subnet ranges in layer 3 broadcast domains
- network function¶
A logical operation and associated packet format applied to specific packet streams at the deployed points in the network
- TCP¶
Transport Control Protocol is the dominant transport protocol in the internet, providing reliable and connection-oriented transport between two end hosts
- DNS¶
Domain Name System (DNS) is a hierarchical and distributed database system that networked systems can query for records of different types for given names
- resource record¶
DNS system records are called resource records (RRs)
- nameserver¶
DNS name services are hosted on nameservers
In DNS, a nameserver will be designated as the authoritative server for the domain names that it has records as designated in the start of authority (SOA) record in its records
- DHCP¶
Dynamic Host Configuration Protocol