Landline and mobile voice-calling wobbled yesterday morning as many worked-from-home for the first time - and then fell over altogether in the afternoon on a 350 per cent surge in the afternoon as people attempted to call each other about the PM's Level 3/4 announcement.
But mobile broadband held up well, allowing people to make calls via the likes of Apple and Facebook apps.
And Chorus says fixed-line broadband had no problems - and despite escalating use, it still has a lot of headroom thanks to upgrades over the past decade associated with the public-private Ultrafast Broadband (UFB) rollout and other projects.
"There's been no congestion on the Chorus network during the day," spokesman Steve Pettigrew told the Herald late Monday.
"Daytime network utilisation increased again beyond the high on Friday reaching 1.37Tbps [terabits per second], up 37% on the baseline [of recent average data consumption].
There was a spike mid-afternoon with the PM's speech, then evening traffic (always the busiest time) was also heavier than usual.
"The evening peak last night was 2.56Tbps, but current capacity allows for a peak of 3.5Tbps."
That beat the spike of 2.44Tbps spike on March 12 - which some might have been tempted to put down to the initial remote working surge, but which Chorus instead pinned on the release of the latest installment of the hit multiplayer game Call of Duty.
"In context, the peak during Rugby World Cup 2019 was 2.6Tbps," Pettigrew says.
"We are expecting a big day today with the schools closing their gates."
Pettigrew did caution though that, "Slow-downs are of course still possible with business IT systems congesting, within broadband retailer networks or at the handover or when accessing content from servers overseas.
"There is also a good case for individuals to look to optimise their home wi-fi networks."
The Telecommunications Forum (TCF), an industry body whose members include Chorus, Spark, Vodafone, Vocus and 2degrees, is working on a simple set of instructions for people to upgrade their wireless networks at home.
Telcos earlier said the Rugby World Cup experience proved their networks could hold up to a remote-networking surge.
The analogy might not have reassured everyone, given patchy RWC streaming at times - but it was apt, in that any internet connection is only as strong as its weakest link.
Aging or poorly positioned hardware can mean that many of the benefits of a fast fibre connection into a home are lost.
Chorus is also working on a relief package for businesses and is liaising with the Ministry of Education on a solution for households without an internet connection. Details are pending. On the retail, fixed-wireless side, Spark last week re-launched its "Jump" programme, which provides broadband access for school children in low-income families.
Chorus and Spark shares have both proved relatively resilient amid the market meltdown. Both made a Herald list of the top five gainers since the outbreak began.
And yesterday as the NZX50 fell 7.6 per cent, their respective losses were limited with Spark down 1.9 per cent to $3.74 and Chorus 3.2 per cent to $6.00.