TCPIP Configuration and Optimization

TCP/IP Configuration and Optimization

So far you have learned about subnetting and configuring network systems in address class ranges in an effort to optimize TCP/IP configuration, but some other points should be mentioned as well. You need to be sure, above all else, that you understand your network configuration and behavior. Although you can take a few steps to fine-tune TCP/IP traffic, network topology plays a big role.

For TCP/IP specifically , there is the TCP/IP Receive Window Size setting, which is the buffer threshold for inbound packets. The default setting for ethernet networks is 17,520 bytes; when this threshold is met, the receiving system sends out an acknowledgement that the data has been received. This process of sending and acknowledging during a data transmission session repeats every 17,520 bytes until all data has been transmitted. As an administrator, you can adjust this acknowledgement setting to optimize transmissions.

Other settings on the network's Physical and Data Link layers are beyond normal administrative control. Maximum Transmission Units (MTUs), for example, are based on the type of network that is installed. For example, 16Mbps token-ring networks have an MTU setting of 17,914 bytes; 4Mbps token-ring networks have an MTU setting of 4,464 bytes. Ethernet deployments are limited to a 1,500 byte MTU setting. As an analogy, think of the MTU as an envelope in which data is carried.

The Maximum Segment Size (MSS) setting determines the largest segment that can be carried in the MTU. (Think of it as the pages of a letter in an envelope.) This setting also varies depending on the framework. Obviously, the MSS for token-ring networks will be larger than the MSS for ethernet networks.

Networks must consider application requirements when implementing certain services and protocols to optimize bandwidth. Quality of service (QoS) can also be implemented on networks to optimize bandwidth. The main issue on most networks is that all the associated networking equipment needs to support the Resource Reservation Protocol (RSVP). Networks also have certain application requirements to consider, such as the following:

• Routers forward traffic on a best-effort basis as they receive it. Video conferencing and streaming media suffer when available bandwidth is low.

• QoS Admission Control Service (QoS ACS) handles bandwidth on a subnet-to-subnet basis.

• Subnet Bandwidth Management (SBM) manages the use of network resources on a subnet.

• RSVP is a signaling protocol that enables sender and receiver systems to set up a reserved QoS session. RSVP messages carry the reservation request in an effort to maintain the QoS session. This is why each router and switch along the communication path between the sender and receiver needs to support RSVP.

• Traffic Control uses the packet classifier to separate packets into queues based on their priority. The Packet Scheduler manages the queues set up by the packet classifier.