| msc { |
| hscale="1.2"; |
| sgsn [label="SGSN"], pcu [label="PCU"], bts [label="BTS"], bsc [label="BSC"]; |
| |
| |||; |
| bts box bsc [label="A-bis connection"]; |
| pcu <: bts [label="Config. parameters"]; |
| pcu rbox pcu [label="listen on UDP socket"]; |
| pcu note sgsn [label="send to SGSN UDP (port 23000)"]; |
| pcu => sgsn [label="NS RESET"]; |
| pcu <= sgsn [label="NS RESET ACK"]; |
| ...; |
| pcu => sgsn [label="NS UNBLOCK"]; |
| pcu <= sgsn [label="NS UNBLOCK ACK"]; |
| pcu box sgsn [label="NS link established"]; |
| ...; |
| pcu => sgsn [label="BVC RESET"]; |
| pcu <= sgsn [label="BVC RESET ACK"]; |
| ...; |
| pcu => sgsn [label="BVC UNBLOCK"]; |
| pcu <= sgsn [label="BVC UNBLOCK ACK"]; |
| pcu box sgsn [label="BSSGP link established"]; |
| |||; |
| } |