When an
application communicates with the Database Engine, the application programming interfaces (APIs) exposed by the
protocol layer formats the communication using a Microsoft-defi ned format
called a tabular data stream (TDS) packet.
The SQL Server Network Interface (SNI) protocol layer on
both the server and client computers encapsulates the TDS packet inside a
standard communication protocol, such as TCP/IP or Named Pipes. On the server
side of the communication, the network libraries are part of the Database
Engine. On the client side, the network libraries are part of the SQL Native
Client. The configuration of the client and the instance of SQL Server
determine which protocol is used.
SQL Server can be confi gured to support multiple protocols
simultaneously, coming from different clients. Each client connects to SQL
Server with a single protocol. If the client program does not know which
protocols SQL Server is listening on, you can
configure the client to attempt
multiple protocols sequentially. The following protocols are available:
Shared Memory The
simplest protocol to use, with no configurable settings. Clients using the Shared Memory protocol can connect
only to a SQL Server instance running on
the same computer, so this protocol is not useful for most database activity.
Use this protocol for troubleshooting when you suspect that the other protocols
are confi gured incorrectly. Clients
using MDAC 2.8 or earlier cannot use the Shared Memory protocol. If such a
connection is attempted, the client is switched to the Named Pipes protocol.
Named Pipes A
protocol developed for local area networks (LANs). A portion 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 The most widely
used protocol over the Internet. TCP/IP can communicate across interconnected
networks of computers with diverse hardware architectures and operating
systems. It includes standards for routing network traffic and offers advanced
security features. Enabling SQL Server to use TCP/IP requires the most
configuration effort, but most networked computers are already properly configured.
Virtual Interface Adapter (VIA) A protocol that works with VIA hardware. This is a
specialized protocol; configuration details are available from your hardware
vendor.
Tabular Data Stream Endpoints
SQL
Server 2008 also allows you to create a TDS endpoint, so that SQL Server
listens on an additional TCP port. During setup, SQL Server automatically
creates an endpoint for each of the four protocols supported by SQL Server, and
if the protocol is enabled, all users have access to it. For disabled
protocols, the endpoint still exists but cannot be used. An additional endpoint
is created for the DAC, which can be used only by members of the sysadmin fixed server
role.
http://www.mybasicknowledge.com/2012/09/sql-server-network-protocols-and.html
http://www.mybasicknowledge.com/2012/09/sql-server-network-protocols-and.html
