When performing a callout notification to a pager using SIP the pager display information must contain special DTMF.
Pager notification is not supported with version 8 and beyond.
| M | Instructs the SIP channel to dial DTMF as tones rather than SIP packets. |
| T | Instructs the SIP channel to dial DTMF using SIP packets. This is the default setting for all new calls. |
| , | Instructs the SIP channel to pause for 1 second. This cannot be preceded by M and if so will be ignored. To perform a pause, always precede it with a T or before an M. |