Spark Sport customers are being urged to look at their home set-up before lashing out at the streaming service.
A flurry of issues during the All Blacks' weekend clash prompted the service to offer refunds and broadcast the game for free.
But Craig Young from the Telecommunications Users Association of New Zealand (TUANZ) says upgrading your technology might reduce problems.
"Forty days until the final, and if people want to see the final on a streaming service they've still got time to look at what they're doing inside their house, and whether their service is ready for it."
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Spark says Sunday night's matches performed well, and coped with the high demand - though many might have been watching on TV instead.
A late surge of subscribers may be to blame for the streaming service's troubles, Young said - not just overwhelming Spark's capacity, but not checking their own gear was up to scratch.
"This was always going to be a concern - people left it too late... You wonder whether that was partly what was happening as well, and they just weren't ready."
Much of the streaming infrastructure is based overseas - Spark said Saturday night's faults were located in the US.
Bringing the infrastructure to New Zealand could be a solution, says Young.
"For example, if the Super Rugby or something like that was taken up by Spark rather than SKY, you might see that technology arrive here because they're going to have to do the production onshore."
Spark says it's reconfiguring how the stream gets to New Zealand.
And anyone hoping to get a refund for Saturday's clash is being warned that time is ticking. A form for refunds on Spark's site reminds customers they have six days to request their money back.
There are three options, including a full refund for just the All Blacks South Africa match.
Anyone with a tournament pass can relinquish it for the full purchase price.