File transfer protocol troubleshooting
File transfer protocol troubleshooting for FTP, SFTP, rsync, TCP, latency, packet loss, networking, and transfer bottlenecks.
18 articles
UDP Packet Loss During NAS Transfers: How to Diagnose and Fix It
Diagnose UDP packet loss during NAS transfers by comparing interface counters, capture drops and controlled tests before changing buffers or network settings.
Point-to-Point File Transfer: How It Works and When to Use It
Understand point-to-point file transfer: direct paths, relays, endpoint availability and verification, with a practical guide to choosing links or folder sync.
How to Upload Large Files from a Browser: Limits, Resume, and Checks
Upload large files from a browser: check service limits, keep resumable progress, diagnose errors and confirm the destination received the files.
File Transfer Stuck at 100%: Check Verification and Finalization
A file transfer stuck at 100% may still be verifying or finalizing. Use logs, read traffic and an acceptance test to find the remaining work.
Small-File Transfer Benchmark: rsync, tar, SFTP, TCP and QUIC
A small-file transfer benchmark across Germany and the US: 65,536 files, rsync, tar, snapshots, raw copies, TCP and QUIC, with 141 ms RTT.
TCP vs UDP File Transfer: What Actually Changes Over a WAN?
TCP delivers bytes reliably and in order; UDP does not. See how QUIC and other file-transfer protocols add reliability, and what to benchmark first.
Synology Drive ShareSync Slow? Fix NAS Sync Speed
Diagnose a slow Synology Drive ShareSync job: upload bandwidth, connection path, small-file overhead, indexing, disks, CPU, filters and the first sync.
How to Speed Up SFTP Over Long Distance
Tune SFTP request depth and buffers, test compression carefully, and fix storage or network limits that slow secure file transfers over distance.
Why Small File Transfers Are Slow (and How to Speed Them Up)
Small file transfers are slow because metadata, open/close work and round trips repeat for every file. Diagnose the bottleneck and test the fixes.
High-Speed File Transfer Over Long Distance
Learn what slows large-file delivery across high-latency networks, which acceleration methods work, and how WarpSend compares with FTP and IBM Aspera.
How to Share Large Files From a Busy Synology NAS
Diagnose slow downloads from a busy Synology NAS and choose scheduling, storage separation, direct transfer, traffic control, or staged delivery.
Why Tailscale NAS File Transfers Are Slow
Diagnose 1–2MB/s NAS transfers over Tailscale by checking direct versus DERP relay paths, NAT, UDP, iperf, storage, SMB, and file count.
Synology QuickConnect Large File Download Fails? A 50GB Guide
Isolate failed Synology downloads with single-file, ZIP and local-disk tests. Check QuickConnect routes, browser resume and delivery alternatives.
Rsync Slow Over WAN? A Bottleneck-First Tuning Guide
Diagnose slow rsync transfers over a WAN, reduce unnecessary scans and checksums, test compression safely, and benchmark large and small files.
Why Is My Upload So Slow? A Bottleneck-First Diagnosis
Diagnose slow uploads by measuring upstream bandwidth, Wi-Fi, competing traffic, storage, service limits, latency, and loss before changing tools or plans.
A Brief History of Fast File Transfer: FTP, TCP, UDP, and QUIC
A short history of fast file transfer, from FTP and TCP limits to UDP-based congestion control, modern acceleration and reproducible benchmarks.
WarpSend vs FTP Benchmark: The 40× Small-File Difference
In recorded tests, WarpSend transferred a folder of 256 small files at about 40× the FTP reference rate. See why batching matters, alongside large-file records above 200 MB/s.
Why Is FTP Slow Over Long Distance? Causes and Fixes
FTP can be fast for one large file, yet collapse on folders over a high-latency route. Learn why file count, RTT, loss, and TCP tuning change the result.