The SQL Server Network Interface (SNI) is a protocol layer that establishes the network connection between the client and the server. It consists of a set of APIs that are used by both the database engine and the SQL Server Native Client i.e SNAC
SQL Server has support for the following protocols:
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Shared memory: Simple and fast, shared memory is the default protocol used to connect from a client running on the same computer as SQL Server. It can only be used locally, has no configurable properties, and is always tried first when connecting from the local machine means The limitation is that the client applications must reside on the same machine where the SQL Server is installed.
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TCP/IP: TCP/IP is the most commonly / the most popular and common protocol widely used throughout the industry today. It communicates across interconnected networks and is a standard for routing network traffics and offers advanced security features.It enables you to connect to SQL Server by specifying an IP address and a port number. Typically, this happens automatically when you specify an instance to connect to. Your internal name resolution system resolves the hostname part of the instance name to an IP address, and either you connect to the default TCP port number 1433 for default instances or the SQL Browser service will find the right port for a named instance using UDP port 1434.
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Named Pipes: This protocol can be used when your application and SQL Server resides on a local area network. A part of memory is used by one process to pass information to another process, so that the output of one is the input of the other. The second process can be local (on the same computer as the first) or remote (on a networked computer). TCP/IP and Named Pipes are comparable protocols in the architectures in which they can be used. Named Pipes was developed for local area networks (LANs) but it can be inefficient across slower networks such as wide area networks (WANs). To use Named Pipes you first need to enable it in SQL Server Configuration Manager (if you’ll be connecting remotely) and then create a SQL Server alias, which connects to the server using Named Pipes as the protocol. Named Pipes uses TCP port 445, so ensure that the port is open on any firewalls between the two computers, including the Windows Firewall.
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VIA: Virtual Interface Adapter is a protocol that enables high-performance communications between two systems. It requires specialized hardware at both ends and a dedicated connection. Like Named Pipes, to use the VIA protocol you fi rst need to enable it in SQL Server Configuration Manager and then create a SQL Server alias that connects to the server using VIA as the protocol. This protocol has been deprecated and will no longer be available in the future versions of SQL Server.
Regardless of the network protocol used, once the connection is established, SNI creates a secure connection to a TDS endpoint
TDS Endpoint : Tabular Data Stream (TDS) Endpoint also known as TSQL.
For Details About SQL Server ENDPOINT , Very good explained blog is http://www.tobuku.com/docs/SQL%20Server%20Endpoint.pdf , Thanks for writer.
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