4.1.1.2 Direct SIP ConnectionDescriptionUsing this feature, the PBX can be used as a gateway to connect with services provided by external SIP servers.In this way, extensions and trunks connected to the PBX can be connected with clients of the external services.PBXExtensionTrunkV-SIPGWIP NetworkPublic NetworkExternalServerExternalClient 001ExternalClient 002ExternalClient 003SIP over TCPConditionsNotice• When this feature is enabled at a site, SIP over TCP is used as the call control protocol. In this case,all SIP line ports at that site will change to TCP/IP fixed operation and the protocol used by existingSIP lines (UDP/IP) cannot be used.• When this feature is enabled at a site, be aware that all installed V-IPGW and V-SIPGW cards at thatsite will be deleted.• When this feature is enabled, the maximum number of usable V-SIPGW channels will be limited to 64channels per site or 256 channels for the system.• When this feature is enabled at a site, V-IPGW cards cannot be used at that site.• Direct SIP connection can be enabled or disabled on a per-site basis. Changes to this setting will bereflected after a system reset is performed for the site.For details, refer to "9.2.2 PBX Configuration—[1-1] Configuration—Slot—SystemProperty—Site—Main— SIP over TCP/IP (V-SIPGW) *)" in the PC Programming Manual.• When this feature is enabled, the supported audio codecs are as follows:Codec Sampling RateG.711 (μ-law) 8 kHzG.711 (a-law) 8 kHzNamed Telephone event 8 kHzComfort noise 8 kHzRED/8000 8 kHz• Inband DTMF signals (except for Flash) received from the PBX's extensions/trunks can be sent to theexternal service clients via the gateway.• It is possible to register several external servers and use the failover feature. For details, see "4.1.1.1 SIPServer Failover".Feature Guide 3794.1.1 SIP (Session Initiation Protocol) Trunk
