Editing Server Message Block (section)

=== Performance ===
The use of the SMB protocol has often correlated with a significant increase in [[broadcast traffic]] on a network. However the SMB itself does not use broadcasts—the broadcast problems commonly associated with SMB actually originate with the [[NetBIOS]] service location protocol.{{clarify|reason=Does this refer to service location via name resolution or via the browser protocol?|date=March 2013}} By default, a [[Microsoft Windows NT 4.0]] server used NetBIOS to advertise and locate services. NetBIOS functions by broadcasting services available on a particular host at regular intervals. While this usually makes for an acceptable default in a network with a smaller number of hosts, increased broadcast traffic can cause problems as the number of hosts on the network increases. The implementation of name resolution infrastructure in the form of [[Windows Internet Naming Service]] (WINS) or [[Domain Name System]] (DNS) resolves this problem. WINS was a proprietary implementation used with Windows NT 4.0 networks, but brought about its own issues and complexities in the design and maintenance of a Microsoft network.

Since the release of Windows 2000, the use of WINS for name resolution has been deprecated by Microsoft, with hierarchical [[Dynamic DNS]] now configured as the default name resolution protocol for all Windows operating systems. Resolution of (short) NetBIOS names by DNS requires that a DNS client expand short names, usually by appending a connection-specific DNS suffix to its DNS lookup queries. WINS can still be configured on clients as a secondary name resolution protocol for interoperability with legacy Windows environments and applications. Further, Microsoft DNS servers can forward name resolution requests to legacy WINS servers in order to support name resolution integration with legacy (pre-Windows 2000) environments that do not support DNS.

[[Network planning and design|Network designers]] have found that [[Network latency|latency]] has a significant impact on the performance of the SMB 1.0 protocol, that it performs more poorly than other protocols like [[File Transfer Protocol|FTP]]. Monitoring reveals a high degree of "chattiness" and a disregard of network latency between hosts.<ref name="barreto">{{cite web|author=Jose Barreto|date=December 9, 2008|title=SMB2, a Complete Redesign of the Main Remote File Protocol for Windows|url=http://blogs.technet.com/josebda/archive/2008/12/05/smb2-a-complete-redesign-of-the-main-remote-file-protocol-for-windows.aspx|access-date=November 1, 2009|publisher=[[Microsoft]] Server & Management Blogs|url-status=dead|archive-url=https://web.archive.org/web/20130112180513/http://blogs.technet.com/b/josebda/archive/2008/12/05/smb2-a-complete-redesign-of-the-main-remote-file-protocol-for-windows.aspx|archive-date=January 12, 2013}}</ref> For example, a [[Virtual private network|VPN]] connection over the [[Internet]] will often introduce network latency. Microsoft has explained that performance issues come about primarily because SMB 1.0 is a block-level rather than a [[Streaming algorithm|streaming]] protocol, that was originally designed for small [[local area network|LANs]]; it has a block size that is limited to 64K, SMB signing creates an additional overhead and the [[TCP tuning|TCP window size]] is not optimized for WAN links.<ref>{{cite web|author=Neil Carpenter|date=October 26, 2004|title=SMB/CIFS Performance Over WAN Links|url=https://docs.microsoft.com/en-us/archive/blogs/neilcar/smbcifs-performance-over-wan-links|url-status=live|archive-url=https://web.archive.org/web/20200213113816/https://docs.microsoft.com/en-us/archive/blogs/neilcar/smbcifs-performance-over-wan-links|archive-date=February 13, 2020|access-date=February 13, 2020|publisher=[[Microsoft]]}}</ref> Solutions to this problem include the updated SMB 2.0 protocol,<ref>{{cite web|title=What's New in SMB in Windows Server|url=https://technet.microsoft.com/en-us/library/hh831474(v=ws.11).aspx|url-status=live|archive-url=https://web.archive.org/web/20170211075409/https://technet.microsoft.com/en-us/library/hh831474(v=ws.11).aspx|archive-date=February 11, 2017|access-date=6 February 2017|website=Microsoft| date=31 August 2016 }}</ref> [[Offline Files]], [[TCP window scale option|TCP window scaling]] and [[WAN optimization]] devices from various network vendors that cache and optimize SMB 1.0<ref>{{cite web|author=Mark Rabinovich, Igor Gokhman|title=CIFS Acceleration Techniques|url=https://www.snia.org/sites/default/orig/sdc_archives/2009_presentations/monday/MarkRabinovich-IgorGokhman-CIFS_Acceleration_Techniques.pdf|access-date=July 6, 2020|publisher=Storage Developer Conference, SNIA, Santa Clara 2009|archive-date=September 30, 2020|archive-url=https://web.archive.org/web/20200930145453/https://www.snia.org/sites/default/orig/sdc_archives/2009_presentations/monday/MarkRabinovich-IgorGokhman-CIFS_Acceleration_Techniques.pdf|url-status=live}}</ref> and 2.0.<ref>{{cite web|author=Mark Rabinovich|title=Accelerating SMB2|url=https://www.snia.org/sites/default/orig/SDC2011/presentations/wednesday/MarkRabinovichAccelerating_SMB2.pdf|access-date=July 6, 2020|publisher=Storage Developer Conference, SNIA, Santa Clara 2011|archive-date=May 31, 2024|archive-url=https://web.archive.org/web/20240531142910/https://www.snia.org/sites/default/orig/SDC2011/presentations/wednesday/MarkRabinovichAccelerating_SMB2.pdf|url-status=live}}</ref>