SIP Trunking versus ISDN PRI

Unified communications are having a major impact on how people will communicate and collaborate. SIP Trunking is enabling this trend by providing voice, video, and rich media capabilities, which traditional ISDN PRI circuits cannot deliver. IntelePeer CoreCloud™ SIP Trunking services provide high quality, secure, communications that can significantly reduce cost and increase flexibility versus legacy T1 PRI connections.

Benefits of SIP Trunking over ISDN PRI

  • Reduce Usage Costs –Save 30% or more on monthly telecom costs and enjoy the added multi-modal communication capabilities SIP trunking enables.
  • Trunk Aggregation: Centralize and eliminate redundant connections. Idle connections at one location to be used for calls at other locations giving you increased flexibility over traditional T1 PRI.
  • Flexibility: Buy the exact number of connections needed and easily expand or contract capacity as required by your business.
  • Improved quality: IntelePeer’s CoreCloudTMplatform keeps your communications on pure IP connections vs. T1 PRI connection, improving voice and video quality and preserving features like HD audio.
  • Simplified Billing: CoreCloud UC bundling options make it easy to get started and simplify monthly invoice review.

SIP Trunking


Usage costs* Local and long distance minutes included Local minutes included, but fixed number of long distance minutes or pay-per-minute for long distanceOn a comparable basis, ISDN PRI service can be 2x the cost of SIP trunking service
Aggregation of trunks and access Centralize and eliminate redundant connectionsBuy exact number of connections needed
(no need to buy in increments of 24)Idle connections at one location to be used for calls at other locationsSIP trunking services typically allow ports to be added or deleted quickly.
T-1 and ISDN PRI access arrangements require that trunks be purchased in bunches of 23 or 24For each T-1 or ISDN PRI access connection, the customer has to rent a 1.544 Mbps dedicated line to the carrier’s serving point
Free features SIP trunking services often include services that charged for on ISDN PRI or T-1 services Features like call transfer may cost $50 per trunk per month, making a SIP option far more advantageous.
Simplified billing and administration Bundling options make it easy to get started and simplify monthly invoice review

  • Per User – Local and long distance service can be priced at a flat rate per user
  • Per Port – Priced like a flat-rate SIP port that is shared by a number of users


Organizations spend considerable time and effort processing and auditing telephone bills, tracking usage, and setting up internal chargebacks.

Have questions about “What is SIP Trunking?” Call us. We’d be glad to help.

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