Thanks alt,
but data.Concatenation in DeliverSm data is null.

Hi Alt,
This in my DeliverSm

{DeliverSm, Length: 174, Status: ESME_ROK, Sequence: 0, SourceAddr: 3333333333, DestAddr: mittente}
base {Inetlab.SMPP.PDU.SmppRequest<Inetlab.SMPP.PDU.DeliverSmResp>}: {DeliverSm, Length: 174, Status: ESME_ROK, Sequence: 0, SourceAddr: 3333333333, DestAddr: mittente ...

I have the same problem, messageLong is 180 char
this is my code :

string ID = "1";
//code for send multiple message asynchronously
byte[] b = Encoding.ASCII.GetBytes(ID);
ISubmitSmBuilder builder = SMS.ForSubmit()
.Text(messageLong)
.From("mittente", AddressTON.International, AddressNPI.ISDN ...