The network was never supposed to be a CX problem. For years, it wasn’t. Telecom engineers leaned on the PSTN’s built-in inefficiency as a quality guarantee, and the broader industry was happy to leave well enough alone.
That era is ending.
With the UK’s PSTN shutdown locked in for January 2027, organizations still routing contact center calls over legacy infrastructure now have a hard deadline. But as Zeus Kerravala, Principal Analyst at ZK Research, makes clear in this conversation, the bigger risk isn’t missing the migration window. It’s treating it as a straight swap.
“You shouldn’t be taking this new technology and making it look like the old technology,” Kerravala says. “It should be, ‘how do I modernize my network and do a bunch of different things.'”
The problem is that modernizing means running voice traffic across shared, IP-based networks, exactly the kind of environment where LLM-driven bots add another 200-300 milliseconds of latency on top of existing SIP delay. When the bot feels slow, someone has to explain why.
Right now, most CX teams don’t have the tools to answer that question.
Kerravala points to Cisco ThousandEyes as one of the few observability platforms that can trace a voice interaction across local, cloud, and public internet infrastructure simultaneously, helping teams move from reactive firefighting to predictive network management. He also flags edge AI inference as a fast-moving development that could significantly cut latency for in-store and regional deployments within the next year.
The organizational piece, though, may be the hardest part. CX and IT have historically operated in separate lanes. Kerravala’s view is that the companies that get ahead of this will be the ones that stop managing unified networks through siloed teams.
