€•q‰      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ"/translations/zh_CN/networking/gtp”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/zh_TW/networking/gtp”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/it_IT/networking/gtp”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/ja_JP/networking/gtp”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/ko_KR/networking/gtp”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/sp_SP/networking/gtp”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒcomment”“”)”}”(hŒ SPDX-License-Identifier: GPL-2.0”h]”hŒ SPDX-License-Identifier: GPL-2.0”…””}”hh£sbah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1h¡hhhžhhŸŒ</var/lib/git/docbuild/linux/Documentation/networking/gtp.rst”h KubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒ%The Linux kernel GTP tunneling module”h]”hŒ%The Linux kernel GTP tunneling module”…””}”(hh»hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hh¶hžhhŸh³h KubhŒdefinition_list”“”)”}”(hhh]”hŒdefinition_list_item”“”)”}”(hŒ]Documentation by
Harald Welte <laforge@gnumonks.org> and
Andreas Schultz <aschultz@tpip.net>
”h]”(hŒterm”“”)”}”(hŒDocumentation by”h]”hŒDocumentation by”…””}”(hhÖhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÔhŸh³h K	hhÐubhŒ
definition”“”)”}”(hhh]”hŒ	paragraph”“”)”}”(hŒKHarald Welte <laforge@gnumonks.org> and
Andreas Schultz <aschultz@tpip.net>”h]”(hŒHarald Welte <”…””}”(hhëhžhhŸNh NubhŒ	reference”“”)”}”(hŒlaforge@gnumonks.org”h]”hŒlaforge@gnumonks.org”…””}”(hhõhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”Œmailto:laforge@gnumonks.org”uh1hóhhëubhŒ> and
Andreas Schultz <”…””}”(hhëhžhhŸNh Nubhô)”}”(hŒaschultz@tpip.net”h]”hŒaschultz@tpip.net”…””}”(hj	  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”Œmailto:aschultz@tpip.net”uh1hóhhëubhŒ>”…””}”(hhëhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Khhæubah}”(h]”h ]”h"]”h$]”h&]”uh1hähhÐubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÎhŸh³h K	hhËubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhh¶hžhhŸh³h Nubhê)”}”(hŒ^In 'drivers/net/gtp.c' you are finding a kernel-level implementation
of a GTP tunnel endpoint.”h]”hŒbIn â€˜drivers/net/gtp.câ€™ you are finding a kernel-level implementation
of a GTP tunnel endpoint.”…””}”(hj5  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Khh¶hžhubhµ)”}”(hhh]”(hº)”}”(hŒWhat is GTP”h]”hŒWhat is GTP”…””}”(hjF  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hjC  hžhhŸh³h Kubhê)”}”(hŒßGTP is the Generic Tunnel Protocol, which is a 3GPP protocol used for
tunneling User-IP payload between a mobile station (phone, modem)
and the interconnection between an external packet data network (such
as the internet).”h]”hŒßGTP is the Generic Tunnel Protocol, which is a 3GPP protocol used for
tunneling User-IP payload between a mobile station (phone, modem)
and the interconnection between an external packet data network (such
as the internet).”…””}”(hjT  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KhjC  hžhubhê)”}”(hXH  So when you start a 'data connection' from your mobile phone, the
phone will use the control plane to signal for the establishment of
such a tunnel between that external data network and the phone.  The
tunnel endpoints thus reside on the phone and in the gateway.  All
intermediate nodes just transport the encapsulated packet.”h]”hXL  So when you start a â€˜data connectionâ€™ from your mobile phone, the
phone will use the control plane to signal for the establishment of
such a tunnel between that external data network and the phone.  The
tunnel endpoints thus reside on the phone and in the gateway.  All
intermediate nodes just transport the encapsulated packet.”…””}”(hjb  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KhjC  hžhubhê)”}”(hŒ The phone itself does not implement GTP but uses some other
technology-dependent protocol stack for transmitting the user IP
payload, such as LLC/SNDCP/RLC/MAC.”h]”hŒ The phone itself does not implement GTP but uses some other
technology-dependent protocol stack for transmitting the user IP
payload, such as LLC/SNDCP/RLC/MAC.”…””}”(hjp  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KhjC  hžhubhê)”}”(hXO  At some network element inside the cellular operator infrastructure
(SGSN in case of GPRS/EGPRS or classic UMTS, hNodeB in case of a 3G
femtocell, eNodeB in case of 4G/LTE), the cellular protocol stacking
is translated into GTP *without breaking the end-to-end tunnel*.  So
intermediate nodes just perform some specific relay function.”h]”(hŒäAt some network element inside the cellular operator infrastructure
(SGSN in case of GPRS/EGPRS or classic UMTS, hNodeB in case of a 3G
femtocell, eNodeB in case of 4G/LTE), the cellular protocol stacking
is translated into GTP ”…””}”(hj~  hžhhŸNh NubhŒemphasis”“”)”}”(hŒ(*without breaking the end-to-end tunnel*”h]”hŒ&without breaking the end-to-end tunnel”…””}”(hjˆ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j†  hj~  ubhŒC.  So
intermediate nodes just perform some specific relay function.”…””}”(hj~  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K hjC  hžhubhê)”}”(hX;  At some point the GTP packet ends up on the so-called GGSN (GSM/UMTS)
or P-GW (LTE), which terminates the tunnel, decapsulates the packet
and forwards it onto an external packet data network.  This can be
public internet, but can also be any private IP network (or even
theoretically some non-IP network like X.25).”h]”hX;  At some point the GTP packet ends up on the so-called GGSN (GSM/UMTS)
or P-GW (LTE), which terminates the tunnel, decapsulates the packet
and forwards it onto an external packet data network.  This can be
public internet, but can also be any private IP network (or even
theoretically some non-IP network like X.25).”…””}”(hj   hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K&hjC  hžhubhê)”}”(hŒŽYou can find the protocol specification in 3GPP TS 29.060, available
publicly via the 3GPP website at http://www.3gpp.org/DynaReport/29060.htm”h]”(hŒfYou can find the protocol specification in 3GPP TS 29.060, available
publicly via the 3GPP website at ”…””}”(hj®  hžhhŸNh Nubhô)”}”(hŒ(http://www.3gpp.org/DynaReport/29060.htm”h]”hŒ(http://www.3gpp.org/DynaReport/29060.htm”…””}”(hj¶  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j¸  uh1hóhj®  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K,hjC  hžhubhê)”}”(hŒšA direct PDF link to v13.6.0 is provided for convenience below:
http://www.etsi.org/deliver/etsi_ts/129000_129099/129060/13.06.00_60/ts_129060v130600p.pdf”h]”(hŒ@A direct PDF link to v13.6.0 is provided for convenience below:
”…””}”(hjË  hžhhŸNh Nubhô)”}”(hŒZhttp://www.etsi.org/deliver/etsi_ts/129000_129099/129060/13.06.00_60/ts_129060v130600p.pdf”h]”hŒZhttp://www.etsi.org/deliver/etsi_ts/129000_129099/129060/13.06.00_60/ts_129060v130600p.pdf”…””}”(hjÓ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jÕ  uh1hóhjË  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K/hjC  hžhubeh}”(h]”Œwhat-is-gtp”ah ]”h"]”Œwhat is gtp”ah$]”h&]”uh1h´hh¶hžhhŸh³h Kubhµ)”}”(hhh]”(hº)”}”(hŒThe Linux GTP tunnelling module”h]”hŒThe Linux GTP tunnelling module”…””}”(hjó  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hjð  hžhhŸh³h K3ubhê)”}”(hŒúThe module implements the function of a tunnel endpoint, i.e. it is
able to decapsulate tunneled IP packets in the uplink originated by
the phone, and encapsulate raw IP packets received from the external
packet network in downlink towards the phone.”h]”hŒúThe module implements the function of a tunnel endpoint, i.e. it is
able to decapsulate tunneled IP packets in the uplink originated by
the phone, and encapsulate raw IP packets received from the external
packet network in downlink towards the phone.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K5hjð  hžhubhê)”}”(hŒâIt *only* implements the so-called 'user plane', carrying the User-IP
payload, called GTP-U.  It does not implement the 'control plane',
which is a signaling protocol used for establishment and teardown of
GTP tunnels (GTP-C).”h]”(hŒIt ”…””}”(hj  hžhhŸNh Nubj‡  )”}”(hŒ*only*”h]”hŒonly”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j†  hj  ubhŒá implements the so-called â€˜user planeâ€™, carrying the User-IP
payload, called GTP-U.  It does not implement the â€˜control planeâ€™,
which is a signaling protocol used for establishment and teardown of
GTP tunnels (GTP-C).”…””}”(hj  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K:hjð  hžhubhê)”}”(hŒèSo in order to have a working GGSN/P-GW setup, you will need a
userspace program that implements the GTP-C protocol and which then
uses the netlink interface provided by the GTP-U module in the kernel
to configure the kernel module.”h]”hŒèSo in order to have a working GGSN/P-GW setup, you will need a
userspace program that implements the GTP-C protocol and which then
uses the netlink interface provided by the GTP-U module in the kernel
to configure the kernel module.”…””}”(hj/  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K?hjð  hžhubhê)”}”(hŒõThis split architecture follows the tunneling modules of other
protocols, e.g. PPPoE or L2TP, where you also run a userspace daemon
to handle the tunnel establishment, authentication etc. and only the
data plane is accelerated inside the kernel.”h]”hŒõThis split architecture follows the tunneling modules of other
protocols, e.g. PPPoE or L2TP, where you also run a userspace daemon
to handle the tunnel establishment, authentication etc. and only the
data plane is accelerated inside the kernel.”…””}”(hj=  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KDhjð  hžhubhê)”}”(hŒŒDon't be confused by terminology:  The GTP User Plane goes through
kernel accelerated path, while the GTP Control Plane goes to
Userspace :)”h]”hŒŽDonâ€™t be confused by terminology:  The GTP User Plane goes through
kernel accelerated path, while the GTP Control Plane goes to
Userspace :)”…””}”(hjK  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KIhjð  hžhubhê)”}”(hŒ^The official homepage of the module is at
https://osmocom.org/projects/linux-kernel-gtp-u/wiki”h]”(hŒ*The official homepage of the module is at
”…””}”(hjY  hžhhŸNh Nubhô)”}”(hŒ4https://osmocom.org/projects/linux-kernel-gtp-u/wiki”h]”hŒ4https://osmocom.org/projects/linux-kernel-gtp-u/wiki”…””}”(hja  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jc  uh1hóhjY  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KMhjð  hžhubeh}”(h]”Œthe-linux-gtp-tunnelling-module”ah ]”h"]”Œthe linux gtp tunnelling module”ah$]”h&]”uh1h´hh¶hžhhŸh³h K3ubhµ)”}”(hhh]”(hº)”}”(hŒ2Userspace Programs with Linux Kernel GTP-U support”h]”hŒ2Userspace Programs with Linux Kernel GTP-U support”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj~  hžhhŸh³h KQubhê)”}”(hŒ·At the time of this writing, there are at least two Free Software
implementations that implement GTP-C and can use the netlink interface
to make use of the Linux kernel GTP-U support:”h]”hŒ·At the time of this writing, there are at least two Free Software
implementations that implement GTP-C and can use the netlink interface
to make use of the Linux kernel GTP-U support:”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KShj~  hžhubhŒbullet_list”“”)”}”(hhh]”(hŒ	list_item”“”)”}”(hŒXOpenGGSN (classic 2G/3G GGSN in C):
https://osmocom.org/projects/openggsn/wiki/OpenGGSN
”h]”hê)”}”(hŒWOpenGGSN (classic 2G/3G GGSN in C):
https://osmocom.org/projects/openggsn/wiki/OpenGGSN”h]”(hŒ$OpenGGSN (classic 2G/3G GGSN in C):
”…””}”(hj¨  hžhhŸNh Nubhô)”}”(hŒ3https://osmocom.org/projects/openggsn/wiki/OpenGGSN”h]”hŒ3https://osmocom.org/projects/openggsn/wiki/OpenGGSN”…””}”(hj°  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j²  uh1hóhj¨  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KWhj¤  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¢  hjŸ  hžhhŸh³h Nubj£  )”}”(hŒAergw (GGSN + P-GW in Erlang):
https://github.com/travelping/ergw
”h]”hê)”}”(hŒ@ergw (GGSN + P-GW in Erlang):
https://github.com/travelping/ergw”h]”(hŒergw (GGSN + P-GW in Erlang):
”…””}”(hjÏ  hžhhŸNh Nubhô)”}”(hŒ"https://github.com/travelping/ergw”h]”hŒ"https://github.com/travelping/ergw”…””}”(hj×  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jÙ  uh1hóhjÏ  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KZhjË  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¢  hjŸ  hžhhŸh³h Nubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ*”uh1j  hŸh³h KWhj~  hžhubeh}”(h]”Œ2userspace-programs-with-linux-kernel-gtp-u-support”ah ]”h"]”Œ2userspace programs with linux kernel gtp-u support”ah$]”h&]”uh1h´hh¶hžhhŸh³h KQubhµ)”}”(hhh]”(hº)”}”(hŒ*Userspace Library / Command Line Utilities”h]”hŒ*Userspace Library / Command Line Utilities”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj  hžhhŸh³h K^ubhê)”}”(hŒ®There is a userspace library called 'libgtpnl' which is based on
libmnl and which implements a C-language API towards the netlink
interface provided by the Kernel GTP module:”h]”hŒ²There is a userspace library called â€˜libgtpnlâ€™ which is based on
libmnl and which implements a C-language API towards the netlink
interface provided by the Kernel GTP module:”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K`hj  hžhubhê)”}”(hŒ http://git.osmocom.org/libgtpnl/”h]”hô)”}”(hj#  h]”hŒ http://git.osmocom.org/libgtpnl/”…””}”(hj%  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j#  uh1hóhj!  ubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kdhj  hžhubeh}”(h]”Œ(userspace-library-command-line-utilities”ah ]”h"]”Œ*userspace library / command line utilities”ah$]”h&]”uh1h´hh¶hžhhŸh³h K^ubhµ)”}”(hhh]”(hº)”}”(hŒProtocol Versions”h]”hŒProtocol Versions”…””}”(hjD  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hjA  hžhhŸh³h Kgubhê)”}”(hŒÔThere are two different versions of GTP-U: v0 [GSM TS 09.60] and v1
[3GPP TS 29.281].  Both are implemented in the Kernel GTP module.
Version 0 is a legacy version, and deprecated from recent 3GPP
specifications.”h]”hŒÔThere are two different versions of GTP-U: v0 [GSM TS 09.60] and v1
[3GPP TS 29.281].  Both are implemented in the Kernel GTP module.
Version 0 is a legacy version, and deprecated from recent 3GPP
specifications.”…””}”(hjR  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KihjA  hžhubhê)”}”(hŒgGTP-U uses UDP for transporting PDUs.  The receiving UDP port is 2151
for GTPv1-U and 3386 for GTPv0-U.”h]”hŒgGTP-U uses UDP for transporting PDUs.  The receiving UDP port is 2151
for GTPv1-U and 3386 for GTPv0-U.”…””}”(hj`  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KnhjA  hžhubhê)”}”(hŒÚThere are three versions of GTP-C: v0, v1, and v2.  As the kernel
doesn't implement GTP-C, we don't have to worry about this.  It's the
responsibility of the control plane implementation in userspace to
implement that.”h]”hŒàThere are three versions of GTP-C: v0, v1, and v2.  As the kernel
doesnâ€™t implement GTP-C, we donâ€™t have to worry about this.  Itâ€™s the
responsibility of the control plane implementation in userspace to
implement that.”…””}”(hjn  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KqhjA  hžhubeh}”(h]”Œprotocol-versions”ah ]”h"]”Œprotocol versions”ah$]”h&]”uh1h´hh¶hžhhŸh³h Kgubhµ)”}”(hhh]”(hº)”}”(hŒIPv6”h]”hŒIPv6”…””}”(hj‡  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj„  hžhhŸh³h Kwubhê)”}”(hŒ†The 3GPP specifications indicate either IPv4 or IPv6 can be used both
on the inner (user) IP layer, or on the outer (transport) layer.”h]”hŒ†The 3GPP specifications indicate either IPv4 or IPv6 can be used both
on the inner (user) IP layer, or on the outer (transport) layer.”…””}”(hj•  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kyhj„  hžhubhê)”}”(hŒ³Unfortunately, the Kernel module currently supports IPv6 neither for
the User IP payload, nor for the outer IP layer.  Patches or other
Contributions to fix this are most welcome!”h]”hŒ³Unfortunately, the Kernel module currently supports IPv6 neither for
the User IP payload, nor for the outer IP layer.  Patches or other
Contributions to fix this are most welcome!”…””}”(hj£  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K|hj„  hžhubeh}”(h]”Œipv6”ah ]”h"]”Œipv6”ah$]”h&]”uh1h´hh¶hžhhŸh³h Kwubhµ)”}”(hhh]”(hº)”}”(hŒMailing List”h]”hŒMailing List”…””}”(hj¼  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj¹  hžhhŸh³h Kubhê)”}”(hXy  If you have questions regarding how to use the Kernel GTP module from
your own software, or want to contribute to the code, please use the
osmocom-net-grps mailing list for related discussion. The list can be
reached at osmocom-net-gprs@lists.osmocom.org and the mailman
interface for managing your subscription is at
https://lists.osmocom.org/mailman/listinfo/osmocom-net-gprs”h]”(hŒÜIf you have questions regarding how to use the Kernel GTP module from
your own software, or want to contribute to the code, please use the
osmocom-net-grps mailing list for related discussion. The list can be
reached at ”…””}”(hjÊ  hžhhŸNh Nubhô)”}”(hŒ"osmocom-net-gprs@lists.osmocom.org”h]”hŒ"osmocom-net-gprs@lists.osmocom.org”…””}”(hjÒ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”Œ)mailto:osmocom-net-gprs@lists.osmocom.org”uh1hóhjÊ  ubhŒ@ and the mailman
interface for managing your subscription is at
”…””}”(hjÊ  hžhhŸNh Nubhô)”}”(hŒ;https://lists.osmocom.org/mailman/listinfo/osmocom-net-gprs”h]”hŒ;https://lists.osmocom.org/mailman/listinfo/osmocom-net-gprs”…””}”(hjæ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jè  uh1hóhjÊ  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kƒhj¹  hžhubeh}”(h]”Œmailing-list”ah ]”h"]”Œmailing list”ah$]”h&]”uh1h´hh¶hžhhŸh³h Kubhµ)”}”(hhh]”(hº)”}”(hŒIssue Tracker”h]”hŒIssue Tracker”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj  hžhhŸh³h K‹ubhê)”}”(hŒ„The Osmocom project maintains an issue tracker for the Kernel GTP-U
module at
https://osmocom.org/projects/linux-kernel-gtp-u/issues”h]”(hŒNThe Osmocom project maintains an issue tracker for the Kernel GTP-U
module at
”…””}”(hj  hžhhŸNh Nubhô)”}”(hŒ6https://osmocom.org/projects/linux-kernel-gtp-u/issues”h]”hŒ6https://osmocom.org/projects/linux-kernel-gtp-u/issues”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j  uh1hóhj  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Khj  hžhubeh}”(h]”Œissue-tracker”ah ]”h"]”Œissue tracker”ah$]”h&]”uh1h´hh¶hžhhŸh³h K‹ubhµ)”}”(hhh]”(hº)”}”(hŒHistory / Acknowledgements”h]”hŒHistory / Acknowledgements”…””}”(hj<  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj9  hžhhŸh³h K’ubhê)”}”(hŒ¿The Module was originally created in 2012 by Harald Welte, but never
completed.  Pablo came in to finish the mess Harald left behind.  But
doe to a lack of user interest, it never got merged.”h]”hŒ¿The Module was originally created in 2012 by Harald Welte, but never
completed.  Pablo came in to finish the mess Harald left behind.  But
doe to a lack of user interest, it never got merged.”…””}”(hjJ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K”hj9  hžhubhê)”}”(hŒ²In 2015, Andreas Schultz came to the rescue and fixed lots more bugs,
extended it with new features and finally pushed all of us to get it
mainline, where it was merged in 4.7.0.”h]”hŒ²In 2015, Andreas Schultz came to the rescue and fixed lots more bugs,
extended it with new features and finally pushed all of us to get it
mainline, where it was merged in 4.7.0.”…””}”(hjX  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K˜hj9  hžhubeh}”(h]”Œhistory-acknowledgements”ah ]”h"]”Œhistory / acknowledgements”ah$]”h&]”uh1h´hh¶hžhhŸh³h K’ubhµ)”}”(hhh]”(hº)”}”(hŒArchitectural Details”h]”hŒArchitectural Details”…””}”(hjq  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hjn  hžhhŸh³h Kubhµ)”}”(hhh]”(hº)”}”(hŒ,Local GTP-U entity and tunnel identification”h]”hŒ,Local GTP-U entity and tunnel identification”…””}”(hj‚  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj  hžhhŸh³h K ubhê)”}”(hŒgGTP-U uses UDP for transporting PDU's. The receiving UDP port is 2152
for GTPv1-U and 3386 for GTPv0-U.”h]”hŒiGTP-U uses UDP for transporting PDUâ€™s. The receiving UDP port is 2152
for GTPv1-U and 3386 for GTPv0-U.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K¢hj  hžhubhê)”}”(hŒœThere is only one GTP-U entity (and therefore SGSN/GGSN/S-GW/PDN-GW
instance) per IP address. Tunnel Endpoint Identifier (TEID) are unique
per GTP-U entity.”h]”hŒœThere is only one GTP-U entity (and therefore SGSN/GGSN/S-GW/PDN-GW
instance) per IP address. Tunnel Endpoint Identifier (TEID) are unique
per GTP-U entity.”…””}”(hjž  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K¥hj  hžhubhê)”}”(hŒÍA specific tunnel is only defined by the destination entity. Since the
destination port is constant, only the destination IP and TEID define
a tunnel. The source IP and Port have no meaning for the tunnel.”h]”hŒÍA specific tunnel is only defined by the destination entity. Since the
destination port is constant, only the destination IP and TEID define
a tunnel. The source IP and Port have no meaning for the tunnel.”…””}”(hj¬  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K©hj  hžhubhê)”}”(hŒ
Therefore:”h]”hŒ
Therefore:”…””}”(hjº  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K­hj  hžhubhŒblock_quote”“”)”}”(hXR  * when sending, the remote entity is defined by the remote IP and
  the tunnel endpoint id. The source IP and port have no meaning and
  can be changed at any time.

* when receiving the local entity is defined by the local
  destination IP and the tunnel endpoint id. The source IP and port
  have no meaning and can change at any time.
”h]”jž  )”}”(hhh]”(j£  )”}”(hŒŸwhen sending, the remote entity is defined by the remote IP and
the tunnel endpoint id. The source IP and port have no meaning and
can be changed at any time.
”h]”hê)”}”(hŒžwhen sending, the remote entity is defined by the remote IP and
the tunnel endpoint id. The source IP and port have no meaning and
can be changed at any time.”h]”hŒžwhen sending, the remote entity is defined by the remote IP and
the tunnel endpoint id. The source IP and port have no meaning and
can be changed at any time.”…””}”(hjÕ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K¯hjÑ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¢  hjÎ  ubj£  )”}”(hŒ¦when receiving the local entity is defined by the local
destination IP and the tunnel endpoint id. The source IP and port
have no meaning and can change at any time.
”h]”hê)”}”(hŒ¥when receiving the local entity is defined by the local
destination IP and the tunnel endpoint id. The source IP and port
have no meaning and can change at any time.”h]”hŒ¥when receiving the local entity is defined by the local
destination IP and the tunnel endpoint id. The source IP and port
have no meaning and can change at any time.”…””}”(hjí  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K³hjé  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¢  hjÎ  ubeh}”(h]”h ]”h"]”h$]”h&]”jø  jù  uh1j  hŸh³h K¯hjÊ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÈ  hŸh³h K¯hj  hžhubhê)”}”(hŒ0[3GPP TS 29.281] Section 4.3.0 defines this so::”h]”hŒ/[3GPP TS 29.281] Section 4.3.0 defines this so:”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h K·hj  hžhubhŒliteral_block”“”)”}”(hX«  The TEID in the GTP-U header is used to de-multiplex traffic
incoming from remote tunnel endpoints so that it is delivered to the
User plane entities in a way that allows multiplexing of different
users, different packet protocols and different QoS levels.
Therefore no two remote GTP-U endpoints shall send traffic to a
GTP-U protocol entity using the same TEID value except
for data forwarding as part of mobility procedures.”h]”hX«  The TEID in the GTP-U header is used to de-multiplex traffic
incoming from remote tunnel endpoints so that it is delivered to the
User plane entities in a way that allows multiplexing of different
users, different packet protocols and different QoS levels.
Therefore no two remote GTP-U endpoints shall send traffic to a
GTP-U protocol entity using the same TEID value except
for data forwarding as part of mobility procedures.”…””}”hj  sbah}”(h]”h ]”h"]”h$]”h&]”h±h²uh1j  hŸh³h K¹hj  hžhubhê)”}”(hX#  The definition above only defines that two remote GTP-U endpoints
*should not* send to the same TEID, it *does not* forbid or exclude
such a scenario. In fact, the mentioned mobility procedures make it
necessary that the GTP-U entity accepts traffic for TEIDs from
multiple or unknown peers.”h]”(hŒBThe definition above only defines that two remote GTP-U endpoints
”…””}”(hj+  hžhhŸNh Nubj‡  )”}”(hŒ*should not*”h]”hŒ
should not”…””}”(hj3  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j†  hj+  ubhŒ send to the same TEID, it ”…””}”(hj+  hžhhŸNh Nubj‡  )”}”(hŒ
*does not*”h]”hŒdoes not”…””}”(hjE  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j†  hj+  ubhŒ° forbid or exclude
such a scenario. In fact, the mentioned mobility procedures make it
necessary that the GTP-U entity accepts traffic for TEIDs from
multiple or unknown peers.”…””}”(hj+  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KÁhj  hžhubhê)”}”(hŒhTherefore, the receiving side identifies tunnels exclusively based on
TEIDs, not based on the source IP!”h]”hŒhTherefore, the receiving side identifies tunnels exclusively based on
TEIDs, not based on the source IP!”…””}”(hj]  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KÇhj  hžhubeh}”(h]”Œ,local-gtp-u-entity-and-tunnel-identification”ah ]”h"]”Œ,local gtp-u entity and tunnel identification”ah$]”h&]”uh1h´hjn  hžhhŸh³h K ubeh}”(h]”Œarchitectural-details”ah ]”h"]”Œarchitectural details”ah$]”h&]”uh1h´hh¶hžhhŸh³h Kubhµ)”}”(hhh]”(hº)”}”(hŒAPN vs. Network Device”h]”hŒAPN vs. Network Device”…””}”(hj~  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¹hj{  hžhhŸh³h KËubhê)”}”(hŒJThe GTP-U driver creates a Linux network device for each Gi/SGi
interface.”h]”hŒJThe GTP-U driver creates a Linux network device for each Gi/SGi
interface.”…””}”(hjŒ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KÍhj{  hžhubhê)”}”(hŒ”[3GPP TS 29.281] calls the Gi/SGi reference point an interface. This
may lead to the impression that the GGSN/P-GW can have only one such
interface.”h]”hŒ”[3GPP TS 29.281] calls the Gi/SGi reference point an interface. This
may lead to the impression that the GGSN/P-GW can have only one such
interface.”…””}”(hjš  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KÐhj{  hžhubhê)”}”(hŒ–Correct is that the Gi/SGi reference point defines the interworking
between +the 3GPP packet domain (PDN) based on GTP-U tunnel and IP
based networks.”h]”hŒ–Correct is that the Gi/SGi reference point defines the interworking
between +the 3GPP packet domain (PDN) based on GTP-U tunnel and IP
based networks.”…””}”(hj¨  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KÔhj{  hžhubhê)”}”(hŒzThere is no provision in any of the 3GPP documents that limits the
number of Gi/SGi interfaces implemented by a GGSN/P-GW.”h]”hŒzThere is no provision in any of the 3GPP documents that limits the
number of Gi/SGi interfaces implemented by a GGSN/P-GW.”…””}”(hj¶  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KØhj{  hžhubhê)”}”(hŒ[3GPP TS 29.061] Section 11.3 makes it clear that the selection of a
specific Gi/SGi interfaces is made through the Access Point Name
(APN)::”h]”hŒŒ[3GPP TS 29.061] Section 11.3 makes it clear that the selection of a
specific Gi/SGi interfaces is made through the Access Point Name
(APN):”…””}”(hjÄ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KÛhj{  hžhubj  )”}”(hXÏ  2. each private network manages its own addressing. In general this
   will result in different private networks having overlapping
   address ranges. A logically separate connection (e.g. an IP in IP
   tunnel or layer 2 virtual circuit) is used between the GGSN/P-GW
   and each private network.

   In this case the IP address alone is not necessarily unique.  The
   pair of values, Access Point Name (APN) and IPv4 address and/or
   IPv6 prefixes, is unique.”h]”hXÏ  2. each private network manages its own addressing. In general this
   will result in different private networks having overlapping
   address ranges. A logically separate connection (e.g. an IP in IP
   tunnel or layer 2 virtual circuit) is used between the GGSN/P-GW
   and each private network.

   In this case the IP address alone is not necessarily unique.  The
   pair of values, Access Point Name (APN) and IPv4 address and/or
   IPv6 prefixes, is unique.”…””}”hjÒ  sbah}”(h]”h ]”h"]”h$]”h&]”h±h²uh1j  hŸh³h Kßhj{  hžhubhê)”}”(hŒIn order to support the overlapping address range use case, each APN
is mapped to a separate Gi/SGi interface (network device).”h]”hŒIn order to support the overlapping address range use case, each APN
is mapped to a separate Gi/SGi interface (network device).”…””}”(hjà  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kéhj{  hžhubhŒnote”“”)”}”(hŒ°The Access Point Name is purely a control plane (GTP-C) concept.
At the GTP-U level, only Tunnel Endpoint Identifiers are present in
GTP-U packets and network devices are known”h]”hê)”}”(hŒ°The Access Point Name is purely a control plane (GTP-C) concept.
At the GTP-U level, only Tunnel Endpoint Identifiers are present in
GTP-U packets and network devices are known”h]”hŒ°The Access Point Name is purely a control plane (GTP-C) concept.
At the GTP-U level, only Tunnel Endpoint Identifiers are present in
GTP-U packets and network devices are known”…””}”(hjô  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kîhjð  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jî  hj{  hžhhŸh³h Nubhê)”}”(hŒ=Therefore for a given UE the mapping in IP to PDN network is:”h]”hŒ=Therefore for a given UE the mapping in IP to PDN network is:”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kòhj{  hžhubjÉ  )”}”(hŒ1* network device + MS IP -> Peer IP + Peer TEID,
”h]”jž  )”}”(hhh]”j£  )”}”(hŒ/network device + MS IP -> Peer IP + Peer TEID,
”h]”hê)”}”(hŒ.network device + MS IP -> Peer IP + Peer TEID,”h]”hŒ.network device + MS IP -> Peer IP + Peer TEID,”…””}”(hj!  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kôhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¢  hj  ubah}”(h]”h ]”h"]”h$]”h&]”jø  jù  uh1j  hŸh³h Kôhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÈ  hŸh³h Kôhj{  hžhubhê)”}”(hŒand from PDN to IP network:”h]”hŒand from PDN to IP network:”…””}”(hjA  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Köhj{  hžhubjÉ  )”}”(hŒ+* local GTP-U IP + TEID  -> network device
”h]”jž  )”}”(hhh]”j£  )”}”(hŒ)local GTP-U IP + TEID  -> network device
”h]”hê)”}”(hŒ(local GTP-U IP + TEID  -> network device”h]”hŒ(local GTP-U IP + TEID  -> network device”…””}”(hjZ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h KøhjV  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¢  hjS  ubah}”(h]”h ]”h"]”h$]”h&]”jø  jù  uh1j  hŸh³h KøhjO  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÈ  hŸh³h Køhj{  hžhubhê)”}”(hŒ…Furthermore, before a received T-PDU is injected into the network
device the MS IP is checked against the IP recorded in PDP context.”h]”hŒ…Furthermore, before a received T-PDU is injected into the network
device the MS IP is checked against the IP recorded in PDP context.”…””}”(hjz  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1héhŸh³h Kúhj{  hžhubeh}”(h]”Œapn-vs-network-device”ah ]”h"]”Œapn vs. network device”ah$]”h&]”uh1h´hh¶hžhhŸh³h KËubeh}”(h]”Œ%the-linux-kernel-gtp-tunneling-module”ah ]”h"]”Œ%the linux kernel gtp tunneling module”ah$]”h&]”uh1h´hhhžhhŸh³h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h³uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¹NŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
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halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”j»  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h³Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(j•  j’  jí  jê  j{  jx  jÿ  jü  j>  j;  j  j~  j¶  j³  j   jý  j6  j3  jk  jh  jx  ju  jp  jm  j  jŠ  uŒ	nametypes”}”(j•  ‰jí  ‰j{  ‰jÿ  ‰j>  ‰j  ‰j¶  ‰j   ‰j6  ‰jk  ‰jx  ‰jp  ‰j  ‰uh}”(j’  h¶jê  jC  jx  jð  jü  j~  j;  j  j~  jA  j³  j„  jý  j¹  j3  j  jh  j9  ju  jn  jm  j  jŠ  j{  uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
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