All you need to Know about SIP and PBX Trunks. @nexogy Empower your communications

1. SIP Trunks and PBX Trunks

2. SIP Trunking is a Voice over Internet Protocol (VoIP) based on the
Session Initiation Protocol (SIP) by which Internet Telephony
Service Providers (ITSPs) deliver Telephone Services and Unified
Communications to customers equipped with SIP-based PBX or
Telephone Systems.

3. A PBX Trunk is used when a customer’s PBX does not have VoIP or SIP enabled
interface. An IAD/CPE, analog or digital, is physically connected to the PBX and
receives phone lines via its Internet Connection.

4. SIP Trunk Configuration Options
• Two-Way SIP Trunk (Analog Phone Line Substitution)
• One-Way SIP Trunk / Inbound (Call Center)
• One-Way SIP Trunk / Outbound (International Calls)
• Two-Way Sip Trunk (Hybrid-Failover Option)

5. Two-Way SIP Trunk (Analog Phone Line Substitution)
For the customer who owns an IP-PBX and needs to make local, long distance and international calls as well as
receive inbound calls.
SIP Trunks are the customer’s lines for all incoming and outgoing calls, just as plain old telephone lines
Through the SIP trunk, the main number will be registered on the E911 service to their physical address.
Remaining direct inward dialing (DID) numbers are routed directly into corresponding users’ phone sets by
mapping them in the IP PBX

6. One-Way SIP Trunk / Inbound (Call Center)
For the customer who owns an IP-PBX, and hosts a call center service for receiving calls only
A SIP trunk with any amount of channels requested by the customer is created. This particular SIP trunk is not
able to make outbound calls of any type; it has dedicated lines for inbound calls only.
Because there is no outbound call ability, E911 service does not need to be registered.
Various phone numbers can route external calls inbound to the SIP trunk for specific treatment, such as toll-free
calls, international phone numbers, local phone numbers, and geo-location recognition.
DID options are possible, as part of the SIP trunk or by assigning dedicated channels. Overflow conditions are
offered to route calls to voicemail.

7. One-Way SIP Trunk / Outbound (International Calls)
For the customer who owns an IP PBX, has service with a traditional local phone company and requires
outbound international calls only.
This particular SIP trunk is not configured for inbound calls, as channels are dedicated for outbound calls only
No phone numbers are routed inbound to the SIP trunk.
E911 service does not need to be registered because this SIP trunk is for international calls only.

8. Two-Way SIP Trunk (Hybrid-Failover Option)
For the customer who owns a PBX (IP PBX or Legacy) with foreign exchange service (FXO)/Digital-T1 Interface
and has a SIP (VoIP) interface
Outbound calls are routed through any available channel, PSTN or SIP trunks. SIP trunks are provisioned for the
VoIP interface
If internet connection is lost, SIP trunks are down. PSTN failover handles inbound and outbound calls
E911 Service should be enabled on both PSTN and SIP trunk side. Caller ID (ANI) can be replicated on the SIP
Trunk side to reflect that of the PSTN

9. Benefits
Enhanced 911 Service
Disaster Recovery
411 Directory Assistance
Manager User Portal for setup and MAC's
Multiple Location Interoperability
Track and Download CDRs through Admin Portal
Add DIDs as needed
Long Distance Bundles available as well as A La Carte as needed
8xx Toll Free Numbers
Direct Operation with IP PBXs with no additional hardware

10. Host Name Provided by nexogy in a domain.com format
Transport UDP or TCP
Tel URI User=Phone
Require RegistrationYES
SIP User Provided by nexogy
SIP Password Provided by nexogy
Authorization ID Provided by nexogy / Usually Username
Codec PCMu/G711
SIP Port 5092
Outbound Proxy Required YES
Outbound Proxy mians01.nexogy.net:5092
Outbound Proxy Failover mians02.nexogy.net:5092
DTMF Mode RFC 2833
Inbound OnlyIf Selected, Number of Channels/Ports
Outbound Only If Selected, Number of Channels/Ports
Bidirectional If Selected, Total Number of Channels/Ports
SIP Trunk Info Provided to Partner/Customer

11. Conclusion
With nexogy SIP Trunking, PSTN connectivity is provided through
nexogy’s IP Network. Now your call travels the majority of its path over
nexogy’s Network instead of on the PSTN and then drops back down
to the destination/facility at the last mile. By implementing nexogy as
the carrier, traditional local and international long distance charges are
dramatically decreased as the call travels mostly over the IP network
and not on the PSTN.