Difference between MSS and MTU
Maximum segment size and maximum transmission unit are essential parameters representing the size of the data packet transmitted into the network. These are important as they enable the user to decide the packet size or frame that can be successfully transferred from one node to another. The user can determine the maximum packet size that can be transferred between the nodes without dropping or splitting if the values of these two parameters are known. It allows the user to transfer the data packets efficiently in the networking.
MSS refers to the maximum TCP Segment Size. This term is used in the network when the three-way handshake establishes the node connection. This method ensures that both nodes meet all the basic conditions required to implement the networking protocol.
MTU is an abbreviation for maximum transmission unit; here, the sender node determines the capacity of the host node in the network to send or receive the block of data as a single unit at a point in time. The maximum Segment Size is more advanced and secure than the maximum transmission unit. MSS is an upgraded version of the MTU.
Maximum Transmission Unit (MTU)
Before starting the data transmission in the network, the node has to compute the largest data packet size that can be shared in the network as a single entity that can be transported by the network link and accepted by the receiver node. The data packet should be such that it could also pass through the intermediary nodes in the network. If the data packet size is set too high, then the data packet is fragmented or even dropped from the network, and if the data packet is too small, then the network resources won't be efficiently utilized. It means that if the maximum transmission unit increases during the data transmission in the network, it represents that a single, strong connection can be established between the nodes, and the data transmission will be efficient. Since the user can send more data at once, that will reduce the data payload on each data packet in the network, which means less redundant data is transmitted.
MTU is used for defining the ability of the host node in the network to send or accept the block of data and files as a single entity at a particular point during the transmission. The node is responsible for determining the most optimal data packet size that can be sent in the network. It is essential for efficiently conveying the data within different nodes in the network. It also affects the routing path in the network. The maximum transmission unit is always greater than the maximum segment size as it includes additional data such as TCP/IP header. It includes the source and destination address.
The user can compute the MTU if the MSS value is provided to the user. The formula for computing the MTU is as follows:
MTU= MSS + 40 (IP and TCP header)
The unit of MTU and MSS is bytes. It contains essential information for successful data transmission in the network. Here the 40 bytes of the data represent the additional data added as data payload to each data packet in the network.
Maximum Segment Size (MSS)
It is a TCP header field that states the bits of the data that represent the maximum amount of data carried by the network packet. It is only implemented in the nodes that use TCP/IP handshake to establish the connection between nodes in the network. The nodes use the three-way handshake to ensure that the basic requirements for the data transmission and implementing the network protocols are implemented in the network.
Both MSS and MTU are used to perform the same task and almost perform the functions. The difference in the working of MSS and MTU is that MSS can only be computed when TCP protocol is implemented in layer 4 of the OSI model.
The three-way handshake is only performed once between the nodes in the network. When the user adds a new node to the network with a server, a handshake is performed between the new node and the server. It starts with adding the header payload file in the header of the TCP. MSS is preferred over MTU as it is more secure than MTU. Most new devices use TCP/IP to connect with the network; therefore, MSS is more commonly implemented. It determines the value by which the data segments' fragmentation in the header will occur at the transport and tunnel mode of the TCP/IP protocol.
MSS is always smaller than MTU as it is the size after excluding the header size. The user can use the Maximum transmission unit to determine the maximum segment size in the node. The formula to compute the MSS is as follows:
MSS = MTU - 40 (IP header + TCP header)
The unit of MSS and MTU is bytes. It contains essential information for successful data transmission in the network. Here the 40 bytes of the data represent the additional data added as data payload to each data packet in the network.
Difference between MSS and MTU
Though both the MSS and MTU perform almost the same functions, there are several differences between MTU and MSS. Some of these are as follows:
| S.No | MSS | MTU |
|---|---|---|
| 1. | MSS is an abbreviation used for maximum segment size. | MTU is the abbreviation used for Maximum Transmission Unit. |
| 2. | It is less than MTU as it does not include TCP/IP header data. | It is greater than MSS. It consists of the data payload and the TCP/IP header data. |
| 3. | It uses a three-way handshake to establish a connection between the node and the server in the network. This method is used for determining the TCP header. | It does not perform a three-way handshake to establish a connection between the server and node or to determine the TCP header. |
| 4. | When using MSS, the MSS does not require fragmentation of the data packets when measured to the comparatively lower value of the MTU protocol. | MSS implements fragmentation on the data packets. The fragmentation is performed to a comparatively lesser value than the MTU protocol. |
| 5. | Since the operation is performed on the data segments, MSS computes and decides the value of segmentation at each layer of transport and tunnel in the OSI model. | Since, it is performed at the data packet in the lower layer of the network. Thus, it does not determine the segmentation performed in each network protocol layer. |
| 6. | MSS cannot transfer the data across the network routers. Thus, it does not determine the data size transmitted between different networks by MSS. | MTU can determine the data packet size that can be transferred using the network gateway. It can decide the maximum data that can be transferred from one router to another in the network. |
| 7. | It requires layer four protocol to compute the MSS in the network. | It requires a layer two protocol to compute the MSS in the network. |
| 8. | It computes the maximum size of the data block or file that can be transmitted in the network. | It computes the maximum data size that can be transferred between the different routing networks. |
| 9. | The formula for MSS is: MSS=MTU-40 |
The formula for MTU is: MTU=MSS+40 |
