You should probably avoid TP-Link products if you’re on a tight bandwidth budget. By design, TP-Link firmware sends six DNS requests and one NTP query every 5 seconds, for a total of 715,4 MB per month.
如果拿 24 小時都開機的 Windows 相比的話，會發現這數字天差地別：
To put this number in context: an always-on Windows device will use around 1,6 KB per month on NTP.
nz 的選擇讓人頗好奇，另外直接把幾個大學的 NTP server 放進去不知道是什麼樣的想法：
TP-Link has hardcoded the following non-configurable NTP servers and server pools in their firmware:
- time.nist.gov, time-a.nist.gov, time-b.nist.gov, time-nw.nist.gov
- au.pool.ntp.org, nz.pool.ntp.org
- 22.214.171.124, 126.96.36.199, 188.8.131.52
The first sets of servers are operated by the US National Institute of Standards and Technology (NIST). The second is the Australian and New Zealand public NTP project time server pools. The IP addresses are owned by universities in Japan, Colorado; US, and Sweden respectively.
而從行為可以看到沒有遵守這些 NTP service 的規範：
The NTP Pool project asks device manufacturers and vendors to register (and optionally sponsor) their own pools through the service (e.g. tplink.pool.ntp.org), and emphasize that they “must absolutely not use the default pool.ntp.org zone names”. They also request that vendors don’t check more often than every 5 minutes at the most.
而且因為沒有地方可以修改這些設定，唯一的解法是不要買 TP-Link 的產品：
You can avoid buying TP-Link products to avoid this problem.
You can’t turn this behavior off in TP-Link’s web administration interface nor in their management app for mobile. You can’t change the NTP server addresses it targets either.