 protocols, selecting, 258-259 assessing, 248 providers, selecting, 256 call load balancing, 251 redundancy issues, 261 emergency call handling, 251 SBC deployments, 260-261 failover rating, 251 security, 261 network demarcation, identifying, bidder background of SIP provider, investigating, 186-188 physical SIP trunk delivery, 251 billing servers provider offerings, 249 post-paid billing servers, 61 real-time billing servers, 61 SP networks, 61-62 312 binding SIP messaging to loopback interface binding SIP messaging to loopback case studies interface, 236 distributed SIP trunking to connect border elements PSTN, 274 chassis, cost of, 48 configurations, 277 redundancy, 132 CUBE configuration, 290-295 box-to-box hardware redundancy, CUCM configuration, 277-289 enterprise architecture, 275 branch locations, transitioning to SIP requirements, 276-277 trunks, 40-41 enterprise connection to SP, 263-266 bundled usage offers, 51 CAC, 274 burstable shared trunks, 52 dial peer configuration, business-to-business interconnect 272-273 deployment scenario, 233-235 DTMF interworking, 271-272 interconnecting between H.323 and SIP, 270-271 MTP configuration, 267-270 CAC (Call Admission Control), CEBP (Communications Enhanced 125, 274 Business Processes), 300 calls per dial-peer, limiting, 126 cellular phones, trends, 18-19 global CAC, 126-127 centralized SIP trunking model, 84-85 call agents, SIP trunking for SP networks, 59-60 call patterns, 94-95 cost, 92 call centers SIP trunking trends, 28-30 DID number portability, 88-89 transitioning to SIP trunks, 38-39 emergency call routing, 93-94 Call Control, 5 geographic boundaries, 89 call load balancing, evaluating, 251 high availability, 93 call routing, 104-105 IP addressing, 95 call spikes, cost of, 53 operational implications, 92 calls carried by SIP trunks, 83 oversubscription, containing, 90 QoS considerations, 91 calls per dial-peer, limiting, 126 capacity planning, 137 regulatory considerations, 90 certification, 185 capital costs, 46 cost of equipment, 47-49 Chambers, Joh