You are here: CSP Developer’s Guide: Internet Protocol > 6 Call Agent > Call Agent Reconnect
In general, scenarios like the one below require call agent to reconnect calls.
A and B are SIP endpoints. C could be an IP/PSTN channel or a DSP resource playing an announcement.
1. A and B are connected in bearer-free mode.
2. B is put on hold.
3. A gets connected to C in bearer mode.
4. C is released.
5. A get reconnected to B.
This section explains two specific reconnect scenarios supported by the CSP. Each scenario includes a call flow and message trace.
Using Third Party Integrated Voice Recognition Equipment
The following call flow assumes endpoints A and B are already connected in bearer-free mode.
Message Trace
Initial State
[0x1004 (4100)] (07,04) <--> [0x1003 (4099)] (07,03) 2-Way Connect (Endpoint A)
[0x1003 (4099)] (07,03) <--> [0x1004 (4100)] (07,04) 2-Way Connect (Endpoint B)
1. Route Control message to Endpoint C (Bearer ON)
H->X
[00 81 00 e8 00 05 ff 00 01 29 02 ff fe 02 03 00 1e 00 19 00 04 00 13 00 02 00 08 00 08 00 02 00 65 00 0f 00
01 0b 00 65 00 02 00 00 03 00 33 00 52 00 09 27 7e 00 03 08 01 00 29 37 00 01 00 29 38 00 07 6c 75 63 65 6e
74 00 29 19 00 05 33 33 33 33 00 29 1b 00 0c 31 30 2e 31 30 2e 36 35 2e 33 37 00 29 24 00 05 33 36 33 38 00
29 3a 00 05 31 32 33 34 00 29 3c 00 05 31 32 33 34 00 29 14 00 01 00]
X->H
[00 14 00 e8 00 05 ff 00 10 01 02 1e 09 00 01 00 39 00 03 00 01 07]
2. Park A-B
H->X
[00 11 00 bf 00 03 ff 00 02 0d 03 00 07 03 0d 03 00 07 04]
X->H [00 07 00 bf 00 03 ff 00 10]
Resulting Channel State
[0x1003 (4099)] (07,03) <-- IDLE, L4 STATE 7
[0x1004 (4100)] (07,04) <-- IDLE, L4 STATE 7
3. Put B on Hold (optional)
H->X
[00 1d 00 44 00 04 ff 00 01 0d 03 00 07 04 00 a7 00 1e 01 03 00 33 00 07 00 01 27 b3 00 01 03]
X->H [00 07 00 44 00 04 ff 00 10]
Resulting Channel State
[0x1003 (4099)] (07,03) <-- IDLE, L4 STATE 7
[0x1004 (4100)] (07,04) <-- IDLE, L4 STATE 7
4. Connecting A to C
H->X
[00 11 00 00 00 06 ff 00 02 0d 03 00 07 03 0d 03 00 01 07]
X->H [00 07 00 00 00 06 ff 00 10]
Resulting Channel State
[0x1003 (4099)] (07,03) <--> [0x25f (0607)] (01,07) 2-Way Connect
[0x1004 (4100)] (07,04) <-- IDLE, L4 STATE 7
[0x25f (0607)] (01,07) <--> [0x287 (0647)] (01,08) 2-Way Connect
[0x287 (0647)] (01,08) <--> [0x25f (0607)] (01,07) 2-Way Connect
5. Releasing C
H->X
[00 11 00 08 00 07 ff 00 02 0d 03 00 01 07 0d 03 00 01 07]
X->H [00 07 00 08 00 07 ff 00 10]
X->H
[00 57 00 69 00 11 ff 00 01 0d 03 00 01 07 02 02 1e 2a 00 05 01 04 00 04 ff ff ff ff 01 05 00 04 00 00 05 e9 01 11 00 04 00 00 05 ee 01 10 00 04 00 03 b1 a0 01 12 00 04 00 03 b4 c0 03 00 33 00 18 00 03 27 4e 00 02 00 10 27 92 00 04 0a 0a 41 65 27 93 00 04 00 00 28 bc]
H->X [00 05 00 69 00 11 ff]
Channel A is parked by L4
X->H [00 0e 00 42 00 3b ff 00 01 0d 03 00 07 03 04 00]
H->X [00 05 00 42 00 3b ff]
Resulting Channel State
[0x1003 (4099)] (07,03) <-- IDLE, L4 STATE 7
[0x1004 (4100)] (07,04) <-- IDLE, L4 STATE 7
6. Reconnecting A to B
H->X
[00 4e 00 05 00 08 ff 00 02 0d 03 00 07 03 0d 03 00 07 04 01 02 03 00 1e 00 08 00 01 01 16 00 02 00 01 03 00 33 00 29 00 01 2a 00 00 23 2a 0e 00 04 0a 0a 41 87 2a 01 00 17 2a 03 00 01 00 2a 07 00 04 00 00 14 f8 2a 02 00 06 2a 08 00 02 00 02]
X->H [00 07 00 05 00 08 ff 00 10]
Resulting Channel State (Same as initial state)
[0x1003 (4099)] (07,03) <--> [0x1004 (4100)] (07,04) 2-Way Connect
[0x1004 (4100)] (07,04) <--> [0x1003 (4099)] (07,03) 2-Way Connect
7. Putting B on 2 way voice path (un hold)
H->X
[00 1d 00 44 00 09 ff 00 01 0d 03 00 07 04 00 a7 00 1e 01 03 00 33 00 07 00 01 27 b3 00 01 00]
X->H [00 07 00 44 00 00 ff 00 10]
In the following call flow there is no third party equipment involved for playing announcements or collecting digits. The CSP uses the resources on the DSP card instead.
Message Trace
Recorded Announcement Connect message (0x0055)
H->X
[00 23 00 55 00 00 01 00 01 0d 03 00 01 00 00 03 0a 02 16 02 17 02 18 02 16 02 16 02 16 02 16 02 16 02 16 02 17]