However, as the SCC had only three bytes of buffer space, it was critical that the ports be read as quickly as possible to prevent a buffer overflow and loss of data. This was not an issue for networking protocols, where lost packets are assumed and dealt with in the network stack, but represented a serious problem for RS-232 data which had no internal form of flow control in the data stream. As a result, performance on a Mac Plus was generally limited to about 9600 bit/s in RS-232 mode, and could only reliably maintain half of that if LocalTalk was active at the same time.