Arduino with GSM SIM 900 Module

Friend, I am doing something similar, but when you start sending me some codes it reports error:

AT+CSTT="bam.entelpcs.cl"

OK
AT+CIICR

OK
AT+CIFSR

10.177.68.41
AT+CIPSPRT=0

OK
AT+CIPSTART="tcp","api.xively.com","8081\

ERROR
AT+CIPSTART="tcp","api.xively.com","8081\

ERROR

appreciate your help