General Idea and Utility of Tethered-Caching
If your household or business consists of multiple Mac and iOS devices, or even PC’s running iTunes and Apple services, tethered-caching is worth a look. While I’ll detail the types of content the caching service works with below, the general idea of tethered-caching is to reduce the amount of internet bandwidth by only downloading OS and app updates (along with the other content detailed below) once. Once the caching service is started, all devices located behind your cable modem (or whatever your gateway is) are available to serve this content via your caching server. The download is cached to the server device, after which your other devices will receive the update. iOS devices receive updates when they are connected via USB-to-Lightning. One other perk is updates that follow the initial download to the server are much faster as no connection to Apple’s Servers is required. This also means updates and other content-related functions can be done offline. This is detailed below as well in the man notes. You can also read more about these ideas in my first article iOS 10.3 brings Tethered-Caching for GarageBand & More.
A small use case example would be an app update like GarageBand on iOS devices. GarageBand comes in at 1.46 GB without any extra content. It’s had around 5 updates in the past 12 months. Round that off to 8 GB – if you’ve got 5 devices using the app that’s 40GB. If you’re using Wi-Fi for backups on multiple devices, including your iCloud content – you can easily be transmitting 100GB per day over wi-fi, along with the internet usage required to download it separately for each device. If you regularly upload gigabytes of Samples or backup files to iCloud – or download music and videos to multiple devices, tethered-caching might be a fit. If you’re using the Network Session for MIDI, or any number of other scenarios, eliminating this traffic is a good idea. Considering reducing traffic congestion, along with speedier updates, and more granular / homogenous control over your home or studio devices. And it goes without saying that if you have to use cellular data for any of this content, tethered-caching will decrease usage.
Extending the concepts below a bit is Mac OS Server. With it, you can enable email, messaging, calendar, xcode, and other types of servers. If you’re using, by example, a multi-computer setup, and want to utilize a 2nd computer for serving sample files, or utilizing it as a secondary processing source for Plugins, or 2 run a 2nd Daw instance, need redundancy for files, or remote access – Server is useful. Additional Command line tools for the server are detailed here: Configure Advanced Cache Settings
Setup and Run Tethered-Caching
What follows is taken from the tethered-caching Manual. From Terminal enter Sudo man tethered-caching, which contains a bit more information than I’ve posted below, where I’ve tried to cull out the key points.
**NOTE** The Link provided in the above image is to the Mac OS Server article on cached content types. So it would seem canonical.
Data Types Supported with Tethered-Caching
The following images are from: https://support.apple.com/en-us/HT204675