redzilla
Topic

Performance

TCP throughput, MTU, QoS, frames and latency.

Learn first

TCP at Full Speed: MTU, Windows & BDP Why a 1 Gbps link can transfer at 100 Mbps: MTU and fragmentation, the TCP window, the bandwidth-delay product, and the latency nobody measures. ≈ 12 min read → QoS for Real: DSCP, Queues & Shaping Mark traffic with DSCP, understand the shaping/policing token bucket, and size jitter buffers for voice and video. ≈ 11 min read →

9 tools

MTU / MSS Calculator

Compute the effective MSS by subtracting Ethernet, VLAN, PPPoE, GRE, IPsec and VXLAN overhead.

TCP Throughput / BDP

Calculate maximum TCP throughput, the bandwidth-delay product (BDP) and the optimal window size.

DSCP / QoS Converter

Translate between QoS markings: DSCP (EF/AFxy/CSx), ToS/IP Precedence, hex/binary and 802.1p CoS, with their meaning.

Ethernet Frame & PPS

Compute Ethernet frame efficiency and packets-per-second at line rate (1G–100G), including preamble, IFG, VLAN and FCS overhead.

Token Bucket (Shaping)

Compute token-bucket parameters for shaping or policing: CIR, Bc, interval Tc and maximum burst, and whether a burst passes.

Jitter Buffer

Size the VoIP/video jitter buffer and compute total mouth-to-ear latency, rated against ITU-T G.114.

Video Bitrate

Estimate the bitrate and file size of a video from resolution, frame rate, codec and quality (bits per pixel).

Firewall Sizing (PPS)

Size a firewall or router: convert throughput into packets per second (with IMIX), concurrent sessions and memory.

Latency Budget

Sum a path latency: serialization per link, propagation per distance and processing per hop, for a given packet size.