ETSI TR 102 607 V1.1.1 (2007-10) Technical Report
Speech Processing, Transmission and Quality Aspects (STQ); TCP IP Stack Parameter Settings for Microsoft Windows XP and Microsoft Windows Vista; Comparison and Recommendations
2 ETSI TR 102 607 V1.1.1 (2007-10)
Reference DTR/STQ-000114m
Keywords configuration, transport
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Contents
Intellectual Property Rights...... 4 Foreword...... 4 1 Scope ...... 5 2 References ...... 5 2.1 Informative references...... 5 3 Abbreviations ...... 6 4 TCP IP Parameter Overview ...... 6 4.1 Overview Table ...... 7 4.2 Parameters found in Windows Vista and XP ...... 8 4.3 Parameters found in Windows Vista only ...... 12 4.4 Parameters found in Windows XP only ...... 16 5 Default TCP IP Stack Settings of Microsoft Operating Systems ...... 19 5.1 Default TCP IP Stack Settings of the Windows XP Operating System ...... 19 5.2 Default TCP IP Stack Settings of the Windows Vista Operating System ...... 20 6 General Recommendations...... 20 6.1 Recommendations for Single Parameters...... 20 7 Changes commonly applied by Software provided by Network Operators (Windows XP) ...... 22 7.1 Exemplary Country A ...... 23 7.2 Exemplary Country B...... 24 7.3 Exemplary Country C...... 24 7.4 Exemplary Country D ...... 25 7.5 Exemplary Country E...... 26 8 Changes commonly applied by Software provided by Network Operators (Windows Vista)...... 26 Annex A: Former Recommendations...... 27 History ...... 29
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Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Speech Processing, Transmission and Quality Aspects (STQ).
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1 Scope
The present document points out some differences between the TCP IP Stack implementations included in the Microsoft Windows XP and Microsoft Windows Vista operating systems by providing an overview of default settings currently used. It gives recommendations on the topic of TCP IP Stack configuration parameter tuning with respect to end-to-end quality of service measurements to be performed in digital wireless networks.
Furthermore, the present document provides an overview of TCP IP parameter configuration changes as commonly applied by software provided for the respective operating system by network operators in order for the end-user to access the operators network.
If not explicitly stated differently, the English versions of Microsoft Windows XP (including Service Pack 2) and Microsoft Windows Vista operation systems shall be taken as reference operating systems for the information provided in the present document.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably, the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the method of access to the referenced document and the full network address, with the same punctuation and use of upper case and lower case letters.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity.
2.1 Informative references
[1] Microsoft TechNet: http://support.microsoft.com/kb/120642.
[2] Microsoft white paper: "TCP/IP Registry Values for Microsoft Windows Vista and Windows Server 'Longhorn'".
[3] Microsoft TechNet: http://technet2.microsoft.com/windowsserver/en/library/db56b4d4-a351- 40d5-b6b1-998e9f6f41c91033.mspx?mfr=true.
[4] ETSI TS 102 250-5 (V1.3.1): "Speech Processing, Transmission and Quality Aspects (STQ); QoS aspects for popular services in GSM and 3G networks; Part 5: Definition of typical measurement profiles".
[5] ETSI TS 102 250 (all parts): "Speech Processing, Transmission and Quality Aspects (STQ); QoS aspects for popular services in GSM and 3G networks".
[6] IETF RFC 1323: "TCP Extensions for High Performance".
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[7] IETF RFC 793: "Transmission Control Protocol".
[8] IETF RFC 1122: "Requirements for Internet Hosts - Communication Layers".
[9] IETF RFC 1256: "ICMP Router Discovery Messages".
[10] IETF RFC 2018: "TCP Selective Acknowledgment Options".
[11] IETF RFC 3481: "TCP over Second (2.5G) and Third (3G) Generation Wireless Networks".
3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
APIPA Automatic Private IP Addressing ARP Address Resolution Protocol DHCP Dynamic Host Configuation Protocol DIX Digital, Intel, Xerox DNS Domain Name System GPRS General Packet Radio Services ICMP Internet Control Message Protocol IGMP Internet Group Management Protocol IP Internet Protocol LAN Local Area Network MSS Maximum Segment Size MTU Maximum Transmission Unit NLBS Network Load Balancing Service RFC Request For Comments RTT Round-Trip Time SACK Selective ACKnowledgment SNAP Sub Network Access Protocol TCP Transmission Control Protocol TTL Time To Live VPN Virtual Private Network
4 TCP IP Parameter Overview
This clause lists all relevant parameters in an overview table, followed by a detailed explanation for each parameter, grouped in three sections:
• Parameters found in both Windows XP and Vista.
• Parameters found in Windows Vista only.
• Parameters found in Windows XP only.
NOTE: Windows XP uses the same TCP IP Stack implementation as Windows Server 2003, while Windows Vista uses the same TCP IP Stack implementation as the upcoming Windows Server 2007/2008 (formerly Windows Server Longhorn).
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4.1 Overview Table
Table 1: Overview of TCP parameters described in the present document
Available: Optional: Parameter name XP Vista XP Vista ArpAlwaysSourceRoute X X ArpRetryCount X ArpUseEtherSNAP X X X DatabasePath X DefaultGateway X X DefaultTTL X X X DisabledComponents X DisableDHCPMediaSense X DisableIPSourceRouting X DisableTaskOffload X Domain X EnableAddrMaskReply X EnableBcastArpReply X EnableDeadGWDetect X X EnableDhcp X EnableICMPRedirect X EnableMulticastForwarding X EnablePMTUBHDetect X X X EnablePMTUDiscovery X X X ForwardBroadcasts X ForwardBufferMemory X X GlobalMaxWindowSize X X Hostname X IGMPLevel X X X IGMPVersion X InterfaceMetric X IPAddress X X IPAutoconfigurationAddress X IPAutoconfigurationEnabled X IPAutoconfigurationMask X IPAutoconfigurationSubnet X IPEnableRouter X X KeepAliveInterval X X X KeepAliveTime X X X MTU X X X NameServer X NumForwardPackets X X PerformRouterDiscovery X SackOpts X X SearchList X SolicitationAddressBcast X SubnetMask X X Tcp1323Opts X X X TcpAckFrequency X TcpDelAckTicks X X X TcpInitialRTT X X TcpFinWait2Delay X TcpMaxConnectRetransmissions X X TcpMaxDataRetransmissions X X X TcpMaxDupAcks X X X TcpNumConnections X X TcpTimedWaitDelay X X X TcpUseRFC1122UrgentPointer X X X TcpWindowSize X X TypeOfInterface X UseZeroBroadcast X X
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4.2 Parameters found in Windows Vista and XP
NOTE 1: Descriptions are taken from Microsoft TechNet, see reference [1].
ArpUseEtherSNAP (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Boolean Valid Range: 0,1 (False or True) Default: 0 (False) Description: Setting this parameter to 1 will force TCP/IP to transmit Ethernet packets using 802.3 SNAP encoding. By default, the stack transmits packets in DIX Ethernet format. It will always receive both formats.
DefaultGateway
Key (XP): Tcpip\Parameters\Interfaces\ID for Adapter Key (Vista) : Tcpip\Parameters\Interfaces\InterfaceGUID Value Type: REG_MULTI_SZ - List of dotted decimal IP addresses Valid Range: Any set of valid IP addresses Default: None Description: This parameter specifies the list of gateways to be used to route packets not destined for a subnet that the computer is directly connected to, and for which a more specific route does not exist. This parameter, if it has a valid value, overrides the DhcpDefaultGateway parameter.
DefaultTTL (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Number of seconds/hops Valid Range: 1-255 Default: 32 for Windows NT version 3.51 Default: 128 for Windows NT version 4.0 Description: Specifies the default Time To Live (TTL) value set in the header of outgoing IP packets. The TTL determines the maximum amount of time an IP packet may live in the network without reaching its destination. It is effectively a limit on the number of routers an IP packet may pass through before being discarded.
EnablePMTUBHDetect (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Boolean Valid Range: 0,1 (False, True) Default: 0 (False) Description: Setting this parameter to 1 (True) causes TCP to try to detect "Black Hole" routers while doing Path MTU Discovery. A "Black Hole" router does not return ICMP Destination Unreachable messages when it needs to fragment an IP datagram with the Don't Fragment bit set. TCP depends on receiving these messages to perform Path MTU Discovery. With this feature enabled, TCP will try to send segments without the Don't Fragment bit set if several retransmissions of a segment go unacknowledged. If the segment is acknowledged as a result, the MSS will be decreased and the Don't Fragment bit will be set in future packets on the connection. Enabling black hole detection increases the maximum number of retransmissions performed for a given segment.
EnablePMTUDiscovery (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Boolean Valid Range: 0,1 (False, True) Default: 1 (True) Description: Setting this parameter to 1 (True) causes TCP to attempt to discover the Maximum Transmission Unit (MTU or largest packet size) over the path to a remote host. By discovering the Path MTU and limiting TCP segments to this size, TCP can eliminate fragmentation at routers along the path that connect networks with different MTUs. Fragmentation adversely affects TCP throughput and network congestion. Setting this parameter to 0 causes an MTU of 576 bytes to be used for all connections that are not to machines on the local subnet.
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IGMPLevel (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Number Valid Range: 0,1,2 Default: 2 Description: This parameter determines to what extent the system supports IP multicasting and participates in the Internet Group Management Protocol. At level 0, the system provides no multicast support. At level 1, the system may only send IP multicast packets. At level 2, the system may send IP multicast packets and fully participate in IGMP to receive multicast packets.
IPAddress
Key (XP): Tcpip\Parameters\Interfaces\ID for Adapter Key (Vista) : Tcpip\Parameters\Interfaces\InterfaceGUID Value Type: REG_MULTI_SZ - List of dotted- decimal IP addresses Valid Range: Any set of valid IP addresses Default: None Description: This parameter specifies the IP addresses of the IP interfaces to be bound to the adapter. If the first address in the list is 0.0.0.0, then the primary interface on the adapter will be configured from DHCP. A system with more than one IP interface for an adapter is called "logically multihomed". There must be a valid subnet mask value in the SubnetMask parameter for each IP address specified in this parameter.
IPEnableRouter
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Boolean Valid Range: 0 or 1 (False or True) Default: 0 (False) Description: Setting this parameter to 1 (True) causes the system to route IP packets between the networks that it is connected to.
KeepAliveInterval (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Time in milliseconds Valid Range: 1 - 0xFFFFFFFF Default: 1 000 (one second) Description: This parameter determines the interval separating keep alive retransmissions until a response is received. Once a response is receive, the delay until the next keep alive transmission is again controlled by the value of KeepAliveTime. The connection will be aborted after the number of retransmissions specified by TcpMaxDataRetransmissions have gone unanswered.
KeepAliveTime (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD - Time in milliseconds Valid Range: 1 - 0xFFFFFFFF Default: 7 200 000 (two hours) Description: The parameter controls how often TCP attempts to verify that an idle connection is still intact by sending a keep alive packet. If the remote system is still reachable and functioning, it will acknowledge the keep alive transmission. Keep alive packets are not sent by default. This feature may be enabled on a connection by an application.
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MTU (Optional in Windows XP)
Key (XP): Tcpip\Parameters\Interfaces\ID for Adapter Key (Vista) : Tcpip\Parameters\Interfaces\InterfaceGUID Value Type: REG_DWORD Number Valid Range: 68 - the MTU of the underlying network Default: 0xFFFFFFFF Description: This parameter overrides the default Maximum Transmission Unit (MTU) for a network interface. The MTU is the maximum packet size in bytes that the transport will transmit over the underlying network. The size includes the transport header. Note that an IP datagram may span multiple packets. Values larger than the default for the underlying network will result in the transport using the network default MTU. Values smaller than 68 will result in the transport using an MTU of 68.
SubnetMask
Key (XP): Tcpip\Parameters\Interfaces\ID for Adapter Key (Vista) : Tcpip\Parameters\Interfaces\InterfaceGUID Value Type: REG_MULTI_SZ - List of dotted decimal IP addresses Valid Range: Any set of valid IP addresses. Default: None Description: This parameter specifies the subnet masks to be used with the IP interfaces bound to the adapter. If the first mask in the list is 0.0.0.0, then the primary interface on the adapter will be configured via DHCP. There must be a valid subnet mask value in the this parameter for each IP address specified in the IPAddress parameter.
Tcp1323Opts (Optional in Windows XP)
Key (Vista/XP): Tcpip\Parameters Value Type: REG_DWORD—number (flags) Valid Range: 0 or 2 0 (disable the use of the TCP timestamps option) 2 (enable the use of the TCP timestamps option) Default: No value. Description: This value controls the use of the RFC 1323 [6] TCP Timestamp option. The default behaviour of the TCP/IP stack is to not use the Timestamp options when initiating TCP connections, but use them if the TCP peer that is initiating communication includes them in their synchronize (SYN) segment.
NOTE 2: Additional information on the valid Range (see reference [3]):
The valid range is 0, 1, 2, 3, with: