#3 Network Core and Packet Switching Vocabulary

Vocabulary flashcards covering core network concepts, routing vs. forwarding, packet switching vs. circuit switching, and the structure of the Internet.

Forwarding

The local router action (also known as switching) of moving arriving packets from a router's input link to the appropriate router output link using a local forwarding table.

Routing

The global network action of determining the source-to-destination paths taken by packets using routing algorithms.

Packet Transmission Delay

The time required to push an $L\text{-bit}$ packet into a link at a rate of $R\text{ bps}$, calculated as $\frac{L}{R}\text{ seconds}$.

Store-and-Forward Transmission

A packet-switching condition where the entire packet must arrive at a router before it can be transmitted onto the next link.

Queueing Delay

Delay experienced when packet arrival rate to a link exceeds its transmission rate for a period of time, causing packets to wait in a buffer.

Packet Loss

The dropping of packets that occurs when arriving packets encounter a router whose memory (buffer) is full.

Circuit Switching

A networking method in which end-to-end resources are allocated and reserved for a call between source and destination, providing dedicated resources and guaranteed performance.

Statistical Multiplexing

The efficient sharing of network link resources in packet switching, where capacity is dynamically allocated on-demand among users with bursty traffic.

Access ISP

An Internet Service Provider that directly connects individual end hosts, home networks, enterprise networks, or mobile networks to the Internet.

Tier-1 ISP

A commercial Internet Service Provider (such as Level 3, Sprint, or AT&T) with national and international coverage operating at the center of the Internet structure.

Internet Exchange Point (IXP)

A physical infrastructure where multiple ISPs establish peering links to exchange traffic directly with one another.

Point-of-Presence (POP)

A router group or location in a provider's network where customer networks connect or where peering with other networks takes place.

Content Provider Network

A private network operated by companies like Google, Akamai, or Amazon that connects data centers to the Internet, often bypassing tier-1 and regional ISPs.