![]() All the data in this TCP packet is also received at once during the reception on the server side, and then the application itself performs the splitting of the underlying data in the TCP packet.įor SCTP packets, one SCTP packet can contain multiple data chunks, and different data chunks can contain different messages from different users, because SCTP packets already differentiate different messages, so it is relatively easy for the server side to read them. How to understand the difference between TCP packets and SCTP packets?Īs an example, when a client sends multiple messages to the server side using TCP protocol, if the messages are very short, TCP may put these small data with different roles into the same TCP packet in order to improve transmission efficiency. When these data need to be transmitted in IP, SCTP will packetize these packets into SCTP packets, each SCTP packet contains a packet header, a control block if needed, and finally a data block. In contrast, TCP transmits a stream of bytes.Ī message in SCTP can be split into multiple data blocks, with all the data in each block coming from the same user. sctp transmits a series of messages, and a message is a set of bytes. SCTP has two main features, the first one is Message-based, which means that SCTP is message-oriented. Since TCP has many drawbacks, what are the features of the new SCTP protocol? If such optimization is not desired, then the PSH flag needs to be set in the TCP packet to make it clear that the request is a delay-free transmission request.įinally TCP is also vulnerable to DOS (denial-of-service) attacks. In addition, in order to improve transmission efficiency and avoid sending multiple small packets, TCP may also optimize it, i.e., wait for multiple small packets to merge them into one large packet. With this strict packet order requirement, unnecessary data delays and message blocking may result.īecause TCP is stream-oriented, in order to mark different records in the data stream, the data in TCP needs some additional markers or encodings to differentiate the records. If B is accepted first, then the receiver will need to have the transmitter retransmit the packet. For example, if a packet is split into three copies labeled A, B, and C, then for the receiver, packet A must be accepted first, followed by B and C. ![]() However, TCP imposes some restrictions on transmission in order to ensure reliable data transfer.įor example, TCP requires a strict order of data transmission in order to ensure the reliability of data transmission. The biggest difference between TCP and UDP is that TCP is reliable, which means that TCP provides a way to transfer data reliably over the Internet. But a product or protocol can’t be perfect, there must be some drawbacks, let’s see what are the drawbacks of TCP. UDP and TCP have been used in a very wide range of applications. What is wrong with TCP? TCP is certainly good, we know that UDP is an unreliable way of transferring messages, while TCP is a reliable way of transferring messages. This article will explain in detail the implementation principles and protocol details of SCTP. Specifically, SCTP provides the message-oriented features of UDP protocol, while providing the reliability, sequential transmission and congestion control features of TCP protocol, and also provides multi-homing and redundant paths to improve resiliency and reliability. It is clear that the SCTP protocol is an enhancement of the TCP and UDP protocols. The transport layer has been widely used TCP and UDP protocols, so why do we have to invent a SCTP protocol? Today’s sctp protocol, known as Stream Control Transmission Protocol, is proposed by the IETF in RFC 4960. We generally focus on the layers above the network layer, such as IPV4 IPV6 in the network layer, TCP UDP in the transport layer, HTTP FTP in the application layer, etc. To talk about network protocols, we can’t leave the seven-layer model of OSI (Open System Interconnection).
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