• The NEC SL2100 system restricts an outgoing call under the following conditions:- SIP configuration failed- SIP registration failed- CPU-C1/VOIPDB daughter board link down- Lack of VOIPDB DSP resource- Lack of bandwidth3.1.2 SIP Trunking SetupUse the following steps to initially set up SIP Trunking for the NEC SL2100 system:1. By default, the NEC SL2100 is assigned a static IP address and runs behind a NAT router.When using an NEC SL2100 on a LAN behind an NAPT router, forward port 5060 to the IP address ofthe NEC SL2100 CPU-C1 (commonly called the SL2100 CPU) since the signaling is handled by theCPU-C1. Then, since the media stream (the speech) uses a large range of ports for the RTP packages,forward the ports (10020~10083) to the IP address of the VOIPDB. Or, use the DMZ option for theVOIPDB. This means that the VOIPDB is not actually behind the firewall. This is achieved byconnecting the VOIPDB to a physical or virtual DMZ port. You can also achieve the same result byport forwarding 10020 to 10083.2. Define the SIP Carrier account information (user name, password, domain name/IP address tothe provider).3. Define the trunk ports as SIP.4. Set the Expire Time.SECTION 4 SIP TRUNK OVERVIEWThis section is an overview of basic SIP trunk behavior, protocols, supported SIP trunking methodsand options, supported CODEC as well as other supported functions of SIP Trunking.4.1 General InformationThe NEC SL2100 SIP Trunks behave like some SIP User Agents (UA). UA is the client applicationused with a particular network protocol.The NEC SL2100 provides a maximum of 31 register IDs and can register these IDs with any SIPserver.A maximum number of 128 SIP trunks can be used with the NEC SL2100 system. The maximumnumber of simultaneous VoIP calls is determined by the number of resources available on theVoIPDB.The NEC SL2100 can connect any SIP server over a NAPT router by one static global IP address.The NEC SL2100 system supports a DNS resolution access and an IP address direct access for SIPservers and supports the sub-address feature with SIP trunk interconnection.4.2 Supported ProtocolsThe following protocols are supported:• SIP (RFC2543 bis04)• SIP RFC3261 Supported [updated version of RFC2543]• The SIP stack has been updated from RFC2543 Base to RFC3261 Base• SDPISSUE 1.0 SL2100Networking Manual 7-3
