| Latency | The time delay in a network system. It's the total time it takes for a piece of data (a packet) to travel from the source to the destination and back again. | |
| Jitter Vs Latency | If it takes 80 ms for a packet to go from Vancouver → London, some packets might take 75 ms, others 90 ms. That inconsistency is jitter. | Latency: The time it takes for your friend to hear your voice after you say “Hello” on a call. Jitter: Sometimes your friend hears your words instantly, other times a bit late or out of sync — your voice sounds choppy. |
| Overhead | The extra resources consumed by a process that are not directly part of the primary task. It's the "cost of doing business" on a network or in a computer system. | Types Protocol, Computational, Management |
| Protocol Overhead | This is the extra data added to your actual data to make it routable and reliable. | Sending a 100-byte message via TCP/IP over Ethernet Your Data: 100 bytes. TCP Header: 20 bytes (adds port numbers, sequence numbers). IP Header: 20 bytes (adds source/destination IP addresses). Ethernet Header & Trailer: 18 bytes (adds MAC addresses & FCS error check). Total Sent: 158 bytes. Overhead: 58 bytes! Over 36% of what's sent is not your original data. |
| Computational Overhead | This is the extra CPU processing power required to perform a task. | Encryption (like SSL/TLS or a VPN).Primary Task: Send data from A to B. Overhead: The CPU cycles required to encrypt the data before sending and decrypt it upon receipt. This is a significant cost for firewalls and servers handling many secure connections. |
| Management Overhead | This refers to the human or system effort required to keep something running. | A Stateless Security List vs. a Stateful NSG.The stateless firewall has lower computational overhead (it doesn't track state) but has higher management overhead because an admin must write twice as many rules. The stateful firewall has higher computational overhead but lower management overhead for the admin. |