Update BUILDFORAP2.md

diff --git a/BUILDFORAP2.md b/BUILDFORAP2.md
index 88ffd0a078c28e64157cd35e613d853819f4220a..d595029e9bc955f35e51b499c2f47f4938e23879 100644 (file)
--- a/BUILDFORAP2.md
+++ b/BUILDFORAP2.md
@@ -5,9 +5,9 @@ Experimental Build Instructions for AirPlay 2
 * Initially, at least, leave the settings in the configuration file at default except as noted below.
 * At the time of writing, May 2, 2021, everything is on the latest version of the software -- macOS 11..3, iOS 14.5, Raspberry Pi OS 5.10.17-v7l+ (Buster), Ubuntu 20.04 -- fully updated.
 * At present, Shairport Sync will compile *but not work* on Raspbian Stretch (thanks JD Smith).
-* AirPlay 2 seems to use a timing system based on the [IEEE-1588 Precision Timing Protocol (PTP)](https://standards.ieee.org/standard/1588-2008.html). Shairport Sync relies on a program called `nqptp` ("Not Quite PTP") to monitor PTP signals. This program uses ports 319 and 320 and replaces any PTP service you have on the computer.
+* AirPlay 2 seems to use a timing system based on the [IEEE-1588 Precision Timing Protocol (PTP)](https://standards.ieee.org/standard/1588-2008.html). Shairport Sync relies on a program called [`nqptp` ("Not Quite PTP")](https://github.com/mikebrady/nqptp) to monitor PTP signals. This program uses ports 319 and 320 and replaces any PTP service you have on the computer.
   In addition, `nqptp` must run with `root` privileges.  
- (FYI, most computers do not have a PTP clock running -- instead, they may use an NTP service to keep the system clock synchronised with world time.)
+ (FYI, most computers do not have a PTP clock running -- instead, they may use a [Network Timing Protocol (NTP)](http://www.ntp.org) service to keep the system clock synchronised with world time.)
 * When Shairport Sync is updated, you should check and update `nqptp` *before* building the update.
 
 Installation Instructions