Specifications

Session Initiated Protocol
Planning and Installation Guide F – 3
• ShoreTel IP phones support in-band G711 DTMF signaling. However, out-of-band
DTMF is required for a SIP device to send DTMF to ShoreTel's voicemail or auto
attendant. SIP INFO or DTMF per RFC 2833 can be used.
• ShoreTel can be configured to use the SIP INFO function for DTMF signaling for
environments where out-of-band DTMF is needed but in which RFC 2833 is not
applicable. Note that SIP tie trunks must use SIP INFO and cannot use RFC 2833
DTMF Relay.
• ShoreTel 6.1 offers support for RFC2833 (DTMF), so if the voicemail server is
down, external callers can now enter an extension using DTMF to ring the
extension of the user they are trying to reach. This allows callers who are accessing
the ShoreTel system over a SIP trunk to have access to the Backup Auto-Attendant
in the same manner as users who are accessing the system via all other trunk
types.
Foreign Language Support
• ShoreTel will support Spanish, French and German (Caller Name, Called Name,
User Name) over SIP tie trunks and service provider trunks, although certain
third-party devices may not be able to display the Spanish or German characters.
Routing with Static and Dynamic Trunks
• From the trunk group perspective, when static and dynamic trunks are used:
• only one trunk group with dynamic trunks is allowed per switch
— outbound calls to this trunk group must be completed based in the registration
table
— calls to the same IP address will not work
— calls to different devices going to the PSTN will be selected randomly
• Trunk groups with static IP addresses will not route calls based on OSE ranges
due to the fact that static trunks do not need registration
— the switch sends the call to the next available trunk instead of sending it to the
correct OSE within the range
— this issue can be solved by creating a trunk group on a per-device basis
• OSE's routed over trunk groups in more than one switch (with dynamic
trunks) will fail
General Feature Limitations
• ShoreTel 6.1 introduces support for Music On Hold (MOH) over SIP trunks. The
capacity limits of MOH switches will not change (i.e. a switch will still be capable
of providing up to 15 streams). However, these streams can be to other switches or
to SIP devices, so customers who were not at the switch capacity limit before may
now find themselves testing the limits of the switch capacity.
• If the ShoreTel server has a conference bridge 4.2 installed, you should not enable
SIP. The conference bridge (eDial version 4.2) is not compatible with a ShoreTel
system that has SIP enabled due to the dynamic RTP port required for SIP.
• 4, 5 and 6-party conference is not supported on a SIP trunk call. That means a
three-party conference call cannot be expanded into a four-party conference call
(using MakeMe) if the 4th party is a SIP trunk. This is planned for a future release.
• 3-way conference on a SIP trunk call uses MakeMe conference ports . A minimum
of 4 MakeMe ports must be configured to support 3-way conferencing.