Back in March, I wrote a blog about the PSTN sunset. But in reality legacy technologies are still in use.  I know this since we still sell them. Certainly, IP is growing and SIP Trunking is growing, but for most companies this means a gradual transition, not a full scale wipeout of existing technology. Why?  Because what they have works.  And because what they have is already paid for, minus any maintenance contracts.  And because it works, and is primarily paid for, it makes sense to continue to use it, and do an orderly transition off it when it makes business sense for the enterprise.

Many companies are moving to SIP trunks as connectivity into the customer premise.  SIP trunks can help enterprises move to cloud-based communications infrastructure over time.  It’s certainly easier to upgrade and have flexibility with a cloud deployment.  We have seen this in Dialogic when we have switched some of our enterprise communications applications to the cloud.  And with these SIP trunks comes an enterprise SBC, to help “protect” the enterprise network from what might come down the SIP Trunk.  This makes total sense for the IP network.

But as I said above, there will still likely be legacy infrastructure in the enterprise that works, that is paid for, etc.  So they’ll want to use it.  In this case, a gateway will be required to be placed between the legacy equipment and the SIP network.  This is why the gradual transition to IP continues and will continue over time.  And this is one of the reason gateways continue in the market and why Dialogic continues to sell them.