SIP Trunking vs Cloud PBX: When an Organization Still Needs Its Own SBC

Once a company grows past a few hundred phones, its phone system choice becomes an infrastructure decision rather than an app selection. It must decide whether to run its own PBX and session border controller while buying SIP trunks, or move everything to a hosted provider. The article explains that the SBC is often overlooked in cost comparisons, since it protects the PBX from SIP scanning, translates between carrier and vendor dialects, manages call admission and failover, and anchors media. Keeping on-premises gear makes sense when the PBX was recently purchased, when it is tied to physical systems like paging or alarms, when contact center tools depend on it, or when a team with real expertise is already in place. The author, from a vendor that sells hosted PBX, acknowledges this bias while noting that retaining your own equipment is sometimes the better answer.