We'll excuse the patois.
The communication pipe is the small diameter (say 1/2" or 3/4" typically) pipe running from the water main to the stopcock or meterbox. The continuation of this pipe from the stopcock to the house is the service pipe. It's all the one pipe really, but the importance of the 2 different names for parts of the same pipe is that the Local Authority or Water Company (UK) are only responsible for the mains and the communication pipe and the householder is responsible for the service pipe.
The gooseneck in the communication pipe is a loop or curve in the pipe intended to relieve stresses in the pipe. If it were run straight into the property, settlement in the garden etc could put the pipe under stress.
JD, October 2008
