Planning and Installation Guide Chapter F: Session Initiation Protocol
Call redirection by SIP devices is not supported.
Park/Unpark is not supported on a SIP trunk call. This is planned for a future
Extension Assignment is not supported on SIP trunks. Outbound trunk hunting
will automatically avoid SIP trunks when placing the call to the Extension
Assignment user. The call to the Extension Assignment user cannot be a SIP trunk;
however, the call to the external party can be a SIP trunk.
Silence detection on trunk-to-trunk transfers is not supported since it requires a
Fax (and modem) redirection is not supported with SIP trunks as only physical
trunks can detect fax tones.
ShoreTel SIP supports two codecs - G.711 and G.729.
G.711 SIP devices that do not support RFC 2833 DTMF cannot send DTMF digits
to Voicemail (VM) or Auto-Attendants (AA).
G.729 only SIP devices cannot talk to VM/AA unless they are configured as
Teleworkers or configured in remote site.
F.1.2.6 Additional Configuration Considerations
SIP Info configuration in a Trunk Group should be enabled if ShoreTel SIP tie
trunks are used.
Overlapping number plans are not allowed between two systems tied with SIP
trunks unless digit translation is used.
When translating digits between two ShoreTel systems tied with SIP trunks, even
system extensions like VM, AA should be properly translated.
SIP devices should either be physically present in the ShoreTel site where the
ShoreGear switch is hosting the SIP trunk or should be out of the ShoreTel
A SIP trunk group cannot host both dynamic and static SIP trunks simultaneously.
A SIP trunk group hosting dynamic SIP trunks cannot span ShoreGear switches.
When ShoreTel is working with Dynamic Trunks:
— Multiple registrations of different numbers using the same IP address is not
supported as ShoreTel uses the last one received. (This is the case of Mediatrix
2102/1402; customers are expected to use only static trunks for these devices.)
When ShoreTel is working with Static Trunks:
— OSE ranges might not work when different SIP devices are part of the same
trunk group. Customers are expected to create a dedicated trunk group for
each device that needs a static trunk.
— Customer must ensure that SIP devices work with static trunks. Routing
problems may occur when the same switch has a dynamic trunk group. These
devices should not be registered with the ShoreTel system.
Director does not show information about the SIP devices registered in a switch.
This information can be accessed by telneting to the switch and issuing the
command print_register_table (applies only to dynamic SIP trunks).