Codeset 7: proprietary elements¶

Evidence tags

✅ tested in emulation · 📖 read from code or tables, not exercised · 🔶 inferred · ❓ unknown · 🔌 hardware-verified (nothing yet). See the overview.

Everything after the 97 shift is codeset 7. The PBX uses it for system-phone functions. The layouts below are read from the PBX's message encoders (📖 Read, none of the layouts was sent on a live call). The meaning of almost all elements is ❓ Unknown.

"7-bit value" is a single octet with bit 7 set: v | 0x80. data is raw bytes.

Id	Layout	Notes
`01`	`01 len data` (len up to 16)	identification string. Phone: `PS130357`. PBX: `DW130958`. ✅ Tested
`02`	`02 len data`	generic data blob. The phone sends it empty in its STATUS (✅ Tested)
`03`	`03 02 a b`	two 7-bit values
`04`	`04 01 a`	one 7-bit value
`05`	`05 02 hi lo`	16-bit value
`08`	`08 01 a`	one 7-bit value
`0a`	`0a len data`	string
`0b`	`0b len a b c data`	three 7-bit header octets, then data. Whether `len` counts the header is not verified. The phone stores up to three of these
`0c`	`0c 01 a`	one 7-bit value
`0e`	`0e 03 a sel b`	`a`, `b` 7-bit values, `sel` is `80`, `81`, `82` or `83`
`11`	`11 len data`	string
`19`	`19 len data`	string. Also appears in SETUP, RELEASE, INFORMATION
`1b`	`1b 01 a`	one 7-bit value
`20`	`20 len data`	string. Used in REGISTER
`22`	`22 len data`	string
`24`	`24 len data`	string
`25`	`25 01 a`	one 7-bit value
`26`	`26 02 82 80`	constant in the registration reply (✅ Tested: accepted by the phone)
`28`	`28 len a b data`	two 7-bit header octets, then data
`40`	`40 01 a`	one 7-bit value (INFORMATION)
`14`, `50`	not decoded

The phone's own element table has 29 ids: 01 02 03 04 05 08 0a 0b 0c 0e 11 14 19 1a 1b 20 22 24 25 26 28 30 40 ... up to 58 (📖 Read, partly). Ids the PBX never sends (1a, 30, ...) are only decoded by the phone.

Which messages carry which elements¶

See the table on Messages. In short: FACILITY carries the large set 02 03 04 05 08 0a 11 0b 0c 0e 22 24 25 14 1b 28; the others carry at most 01 11 19 20 25 26 40.

System facility¶

System-phone functions use FACILITY (62) with a facility element that names a function and then the codeset 7 data:

62  1c 02 95 <N|80>  97  <codeset 7 elements>

95 is the profile octet that marks a system phone (standard supplementary services use 91). N is a selector the PBX application chooses; values 3, 4, 7, 11 and 12 were seen in the PBX's code. The phone's own REGISTER messages use N = 12 (1c 02 95 92).

❓ Unknown: which call context the phone requires. A FACILITY on an unknown call reference is answered with RELEASE COMPLETE cause 81, and no element in the table changed the display or LEDs when sent that way (✅ Tested). FACILITY on a live call, or inside a call set up by the phone, has not been tried.

Phone to PBX¶

INFORMATION messages from the phone carry codeset 7 elements for key events (📖 Read from the phone's message builders, not seen in emulation):

header 97, element 06 01 81 or 06 01 82;
for one sub-type also 03 02 hi lo, with hi, lo the high and low nibble of a key code, each OR 0x80;
for other sub-types 05 02 a b, a 16-bit identifier, for example a key or line number.

Which function key produces which code is ❓ Unknown.