TBufferedTransport split Tcp data bug in nodeJs

when i use TBufferedTransport in client and server, the problem is:
1)my thrift file is :namespace js com.thrift
struct User {
1: i32 uid,
2: string name,
3: i16 age,
4: string desc
}
service UserService {
string add(1: User user)
}
2) client:
I execute add() method 3 times, but response is only 1 times.
for example:
client.add(user, function(err, response) {
console.log("response-1:", response);
});
client.add(user, function(err, response) {
console.log("response-2:", response);
});
client.add(user, function(err, response) {
console.log("response-3:", response);
});

Please help me to solve this problem!