Table of Contents
natping_interval (integer)ping_nated_only (integer)natping_partitions (integer)natping_socket (string)received_avp (str)force_socket (string)sipping_bflag (string)remove_on_timeout_bflag (string)sipping_latency_flag (string)sipping_ignore_rpl_codes (CSV string)sipping_from (string)sipping_method (string)nortpproxy_str (string)natping_tcp (integer)oldip_skip (string)ping_threshold (int)max_pings_lost (int)cluster_id (integer)cluster_sharing_tag (string)List of Tables
List of Examples
natping_interval parameterping_nated_only parameternatping_partitions parameternatping_socket parameterreceived_avp parameterforce_socket parametersipping_bflag parameterremove_on_timeout_bflag parametersipping_latency_flag parametersipping_ignore_rpl_codes parametersipping_from parametersipping_method parameternortpproxy_str parameternatping_tcp parameteroldip_skip parameterping_threshold parametermax_pings_lost parametercluster_id parametercluster_sharing_tag parameterfix_nated_contact usagefix_nated_sdp usageadd_rcv_paramer usagefix_nated_register usagenat_uac_test usagenh_enable_ping usageThis is a module to help with NAT traversal. In particular, it helps symmetric UAs that don't advertise they are symmetric and are not able to determine their public address. fix_nated_contact rewrites Contact header field with request's source address:port pair. fix_nated_sdp adds the active direction indication to SDP (flag 0x01) and updates source IP address too (flag 0x02).
Since version 2.2, stateful ping(only SIP Pings) for nathelper is available. This allows you to remove contacts from usrloc location table when max_pings_lost pings are not responded to, each ping having a response timeout of ping_threshold seconds. In order to have this functionality, contacts must have remove_on_timeout_bflag flag set when inserted into the location table.
Works with multipart messages that contain an SDP part, but not with multi-layered multipart messages.
Currently, the nathelper module supports two types of NAT pings:
UDP package - 4 bytes (zero filled) UDP packages are sent to the contact address.
Advantages: low bandwitdh traffic, easy to generate by OpenSIPS;
Disadvantages: unidirectional traffic through NAT (inbound - from outside to inside); As many NATs do update the bind timeout only on outbound traffic, the bind may expire and closed.
SIP request - a stateless SIP request is sent to the contact address.
Advantages: bidirectional traffic through NAT, since each PING request from OpenSIPS (inbound traffic) will force the SIP client to generate a SIP reply (outbound traffic) - the NAT bind will be surely kept open. Since version 2.2, one can also choose to remove contacts from the location table if a certain threshold is detected.
Disadvantages: higher bandwitdh traffic, more expensive (as time) to generate by OpenSIPS;
The following modules must be loaded before this module:
usrloc module - only if the NATed contacts are to be pinged.
clusterer - only if "cluster_id" option is enabled.
Period of time in seconds between sending the NAT pings to all currently registered UAs to keep their NAT bindings alive. Value of 0 disables this functionality.
Enabling the NAT pinging functionality will force the module to bind itself to USRLOC module.
Default value is 0.
If this variable is set then only contacts that have “behind_NAT” flag in user location database set will get ping.
Default value is 0.
How many partitions/chunks to be used for sending the pingings. One partition means sending all pingings together. Two partitions means to send half pings and second half at a time.
Default value is 1. Maximum allowed value is 8.
Example 1.3. Set natping_partitions parameter
...
modparam("nathelper", "natping_partitions", 4)
...
Spoof the natping's source-ip to this address. Works only for IPv4.
Default value is NULL.
Example 1.4. Set natping_socket parameter
...
modparam("nathelper", "natping_socket", "192.168.1.1:5006")
...
The name of the Attribute-Value-Pair (AVP) used to store the URI containing the received IP, port and protocol. The URI is created by the fix_nated_register() function and this data may then be also picked up by the registrar module, which will attach a "Received=" attribute to the registration. Do not forget to change the value of corresponding parameter in the registrar module whenever you change the value of this parameter.
You must set this parameter if you use fix_nated_register(). Additionally, if you are using registrar, you must also set its symmetric received_avp module parameter to the same value.
Default value is "NULL" (disabled).
Example 1.5. Set received_avp parameter
...
modparam("nathelper", "received_avp", "$avp(received)")
...
Sending socket to be used for pinging contacts without local socket information (the local socket information may be lost during a restart or contact replication). If no one specified, OpenSIPS will choose the first listening interface matching the destination protocol and AF family.
Default value is “NULL”.
Example 1.6. Set force_socket parameter
...
modparam("nathelper", "force_socket", "localhost:33333")
...
What branch flag should be used by the module to identify NATed contacts for which it should perform NAT ping via a SIP request instead if dummy UDP package.
Default value is NULL (disabled).
Example 1.7. Set sipping_bflag parameter
...
modparam("nathelper", "sipping_bflag", "SIPPING_ENABLE")
...
What branch flag to be used in order to activate usrloc contact removal when the ping_threshold is exceeded.
Default value is NULL (disabled).
Example 1.8. Set remove_on_timeout_bflag parameter
...
modparam("nathelper", "remove_on_timeout_bflag", "SIPPING_RTO")
...
The branch flag which will be used in order to enable contact pinging latency computation and reporting via the usrloc E_UL_LATENCY_UPDATE event.
Default value is NULL (disabled).
Example 1.9. Set sipping_latency_flag parameter
...
modparam("nathelper", "sipping_latency_flag", "SIPPING_CALC_LATENCY")
...
A comma-separated list of SIP reply status codes to contact pings which are to be discarded. This may be useful for "full-sharing" user location topologies, where the location nodes are not directly facing the UAs, hence the intermediary SIP component may generate replies to offline contact ping attempts (e.g. 408 - Request Timeout) -- such ping replies should be ignored.
Default value is "NULL" (all reply status codes are accepted).
Example 1.10. Set sipping_ignore_rpl_codes parameter
...
modparam("nathelper", "sipping_ignore_rpl_codes", "408, 480, 404")
...
The parameter sets the SIP URI to be used in generating the SIP requests for NAT ping purposes. To enable the SIP request pinging feature, you have to set this parameter. The SIP request pinging will be used only for requests marked so.
Default value is “NULL”.
Example 1.11. Set sipping_from parameter
...
modparam("nathelper", "sipping_from", "sip:pinger@siphub.net")
...
The parameter sets the SIP method to be used in generating the SIP requests for NAT ping purposes.
Default value is “OPTIONS”.
The parameter sets the SDP attribute used by nathelper to mark the packet SDP informations have already been mangled.
If empty string, no marker will be added or checked.
The string must be a complete SDP line, including the EOH (\r\n).
Default value is “a=nortpproxy:yes\r\n”.
Example 1.13. Set nortpproxy_str parameter
...
modparam("nathelper", "nortpproxy_str", "a=sdpmangled:yes\r\n")
...
If the flag is set, TCP/TLS clients will also be pinged with SIP OPTIONS messages.
Default value is 0 (not set).
Parameter which specifies whether old media ip and old origin ip shall be put in the sdp body. The parameter has two values : 'o' ("a=oldoip" field shall be skipped) and 'c' ("a=oldcip" field shall be skipped).
Default value is 0 (not set).
If a contact does not respond in ping_threshold seconds since the ping has been sent, the contact shall be removed after max_pings_lost unresponded pings.
Default value is 3 (seconds).
Number of unresponded pings after which the contact shall be removed from the location table.
Default value is 3 (pings).
The ID of the cluster the module is part of. The clustering support is used by the nathelper module for controlling the pinging process. When part of a cluster of multiple nodes, the nodes can agree upon which node is the one responsible for pinging.
The clustering with sharing tag support may be used to control which node in the cluster will perform the pinging/probing to the contacts. See the cluster_sharing_tag option.
For more info on how to define and populate a cluster (with OpenSIPS nodes) see the "clusterer" module.
Default value is “0 (none)”.
Example 1.18. Set cluster_id parameter
...
# Be part of cluster ID 9
modparam("nathelper", "cluster_id", 9)
...
The name of the sharing tag (as defined per clusterer modules) to control which node is responsible for perform pinging of the contacts. If defined, only the node with active status of this tag will perform the pinging.
The cluster_id must be defined for this option to work.
This is an optional parameter. If not set, all the nodes in the cluster will individually do the pinging.
Default value is “empty (none)”.
Example 1.19. Set cluster_sharing_tag parameter
...
# only the node with the active "vip" sharing tag will perform pinging
modparam("nathelper", "cluster_id", 9)
modparam("nathelper", "cluster_sharing_tag", "vip")
...
Rewrites the URI Contact HF to contain request's source address:port. If a list of URI parameter is provided, it will be added to the modified contact;
IMPORTANT NOTE: Changes made by this function shall not be seen in the async resume route. So make sure you call it in all the resume routes where you need the contact fixed.
Parameters:
uri_params (string, optional)
This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE.
Example 1.20. fix_nated_contact usage
...
if (search("User-Agent: Cisco ATA.*") {
fix_nated_contact(";ata=cisco");
} else {
fix_nated_contact();
}
...
Alters the SDP information in orer to facilitate NAT traversal. What changes to be performed may be controled via the “flags” parameter. Since version 1.12 the name of the old ip fields are "a=oldoip" for old origin ip and "a=oldcip" for old meda ip.
Meaning of the parameters is as follows:
flags (string) - the value may be a CSV of the following flags:
add-dir-active - (old 0x01 flag) adds “a=direction:active” SDP line;
rewrite-media-ip - (old 0x02 flag) rewrite media IP address (c=) with source address of the message or the provided IP address (the provided IP address takes precedence over the source address).
add-no-rtpproxy - (old 0x04 flag) adds “a=nortpproxy:yes” SDP line;
rewrite-origin-ip - (old 0x08 flag) rewrite IP from origin description (o=) with source address of the message or the provided IP address (the provided IP address takes precedence over the source address).
rewrite-null-ips - (old 0x10 flag) force rewrite of null media IP and/or origin IP address. Without this flag, null IPs are left untouched.
ip_address (string, optional) - IP to be used for rewriting SDP. If not specified, the received signalling IP will be used. NOTE: For the IP to be used, you need to use 0x02 or 0x08 flags, otherwise it will have no effect.
sdp_fields (string, optional) - SDP field(s) to be appended to SDP. Note: Each SDP field must be preceded by "\r\n".
This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.
Example 1.21. fix_nated_sdp usage
...
# Add "a=direction:active" SDP line
# Rewrite media IP (c= line)
# Add extra "a=x-attr1" SDP line
# Add extra "a=x-attr2" SDP line
if (search("User-Agent: Cisco ATA.*")
{fix_nated_sdp(3,,"\r\na=x-attr1\r\na=x-attr2");};
...
Add received parameter to Contact header fields or Contact URI. The parameter will contain URI created from the source IP, port, and protocol of the packet containing the SIP message. The parameter can be then processed by another registrar, this is useful, for example, when replicating register messages using t_replicate function to another registrar.
Meaning of the parameters is as follows:
flag (int, optional) - flags to indicate if the parameter should be added to Contact URI or Contact header. If the flag is non-zero, the parameter will be added to the Contact URI. If not used or equal to zero, the parameter will go to the Contact header.
This function can be used from REQUEST_ROUTE.
Example 1.22. add_rcv_paramer usage
... add_rcv_param(); # add the parameter to the Contact header .... add_rcv_param(1); # add the parameter to the Contact URI ...
The function creates a URI consisting of the source IP, port and protocol and stores it in the received_avp AVP. The URI will be appended as "received" parameter to Contact in 200 OK and may also be stored in the user location database if the same AVP is also configured for the registrar module.
This function can be used from REQUEST_ROUTE.
Determines whether the received SIP message originated behind a NAT, using one or more pre-defined checks.
The flags (string) parameter denotes a comma-separated list of checks to be performed, as follows:
private-contact - (old 1 flag) Contact header field is searched for occurrence of RFC1918 / RFC6598 addresses
diff-ip-src-via - (old 2 flag) the "received" test is used: address in Via is compared against source IP address of signaling
private-via - (old 4 flag) Top Most VIA is searched for occurrence of RFC1918 / RFC6598 addresses
private-sdp - (old 8 flag) SDP is searched for occurrence of RFC1918 / RFC6598 addresses
diff-port-src-via - (old 16 flag) test if the source port is different from the port in Via
diff-ip-src-contact - (old 32 flag) address in Contact is compared against source IP address of signaling
diff-port-src-contact - (old 64 flag) Port in Contact is compared against source port of signaling
carrier-grade-nat - (old 128 flag) also include RFC 6333 addresses in the checks for Contact, Via and SDP
Returns true if any of the tests passed.
This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE, FAILURE_ROUTE, BRANCH_ROUTE.
Example 1.24. nat_uac_test usage
...
# check for private Contact or SDP media IP addresses
if (nat_uac_test("private-contact,private-sdp"))
xlog("SIP message is NAT'ed (Call-ID: $ci)\n");
...
Gets or sets the natpinging status.
Parameters:
status (optional) - if not provided the function returns the current natping status. Otherwise, enables natping if parameter value greater than 0 or disables natping if parameter value is 0.
Example 1.25. nh_enable_ping usage
... $ opensips-cli -x mi nh_enable_ping Status:: 1 $ $ opensips-cli -x mi nh_enable_ping 0 $ $ opensips-cli -x mi nh_enable_ping Status:: 0 $ ...
2.1. | Where can I find more about OpenSIPS? |
Take a look at https://opensips.org/. | |
2.2. | Where can I post a question about this module? |
First at all check if your question was already answered on one of our mailing lists:
E-mails regarding any stable OpenSIPS release should be sent to
If you want to keep the mail private, send it to
| |
2.3. | How can I report a bug? |
Please follow the guidelines provided at: https://github.com/OpenSIPS/opensips/issues. |
Table 3.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
| Name | DevScore | Commits | Lines ++ | Lines -- | |
|---|---|---|---|---|---|
| 1. | Bogdan-Andrei Iancu (@bogdan-iancu) | 156 | 123 | 2050 | 873 |
| 2. | Maksym Sobolyev (@sobomax) | 153 | 45 | 3556 | 4790 |
| 3. | Liviu Chircu (@liviuchircu) | 49 | 39 | 438 | 313 |
| 4. | Ionut Ionita (@ionutrazvanionita) | 40 | 15 | 1598 | 627 |
| 5. | Razvan Crainea (@razvancrainea) | 33 | 27 | 158 | 240 |
| 6. | Daniel-Constantin Mierla (@miconda) | 22 | 17 | 142 | 124 |
| 7. | Anca Vamanu | 22 | 4 | 1602 | 185 |
| 8. | Andrei Pelinescu-Onciul | 21 | 17 | 121 | 110 |
| 9. | Jan Janak (@janakj) | 21 | 11 | 780 | 129 |
| 10. | Vlad Patrascu (@rvlad-patrascu) | 19 | 11 | 261 | 268 |
All remaining contributors: Jiri Kuthan (@jiriatipteldotorg), Ancuta Onofrei, Ovidiu Sas (@ovidiusas), Vlad Paiu (@vladpaiu), Andrei Dragus, Henning Westerholt (@henningw), Dan Pascu (@danpascu), Christophe Sollet (@csollet), Marcus Hunger, Klaus Darilion, Sergio Gutierrez, Peter Lemenkov (@lemenkov), Nils Ohlmeier, Emmanuel Buu, Carsten Bock, Shlomi Gutman, Jeremie Le Hen, Bayan Towfiq, Laurent Schweizer, Jasper Hafkenscheid (@hafkensite), Konstantin Bokarius, Alexandra Titoc, John Riordan, Walter Doekes (@wdoekes), Elena-Ramona Modroiu, Nick Altmann (@nikbyte), Edson Gellert Schubert.
(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)
(2) including any documentation-related commits, excluding merge commits. Regarding imported patches/code, we do our best to count the work on behalf of the proper owner, as per the "fix_authors" and "mod_renames" arrays in opensips/doc/build-contrib.sh. If you identify any patches/commits which do not get properly attributed to you, please submit a pull request which extends "fix_authors" and/or "mod_renames".
(3) ignoring whitespace edits, renamed files and auto-generated files
Table 3.2. Most recently active contributors(1) to this module
| Name | Commit Activity | |
|---|---|---|
| 1. | Alexandra Titoc | Sep 2024 - Sep 2024 |
| 2. | Bogdan-Andrei Iancu (@bogdan-iancu) | Nov 2003 - Jun 2024 |
| 3. | Liviu Chircu (@liviuchircu) | Jan 2013 - May 2024 |
| 4. | Maksym Sobolyev (@sobomax) | May 2003 - Nov 2023 |
| 5. | Vlad Paiu (@vladpaiu) | Aug 2010 - Jul 2023 |
| 6. | Vlad Patrascu (@rvlad-patrascu) | May 2017 - Apr 2023 |
| 7. | Nick Altmann (@nikbyte) | May 2022 - May 2022 |
| 8. | Peter Lemenkov (@lemenkov) | Jun 2018 - Apr 2022 |
| 9. | Razvan Crainea (@razvancrainea) | Dec 2010 - Jan 2021 |
| 10. | Jasper Hafkenscheid (@hafkensite) | Mar 2020 - Mar 2020 |
All remaining contributors: Dan Pascu (@danpascu), Shlomi Gutman, Ovidiu Sas (@ovidiusas), Ionut Ionita (@ionutrazvanionita), Walter Doekes (@wdoekes), Christophe Sollet (@csollet), Anca Vamanu, John Riordan, Emmanuel Buu, Andrei Dragus, Sergio Gutierrez, Klaus Darilion, Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Henning Westerholt (@henningw), Ancuta Onofrei, Marcus Hunger, Carsten Bock, Jeremie Le Hen, Laurent Schweizer, Bayan Towfiq, Andrei Pelinescu-Onciul, Elena-Ramona Modroiu, Jiri Kuthan (@jiriatipteldotorg), Jan Janak (@janakj), Nils Ohlmeier.
(1) including any documentation-related commits, excluding merge commits
Last edited by: Liviu Chircu (@liviuchircu), Vlad Patrascu (@rvlad-patrascu), Nick Altmann (@nikbyte), Jasper Hafkenscheid (@hafkensite), Razvan Crainea (@razvancrainea), Bogdan-Andrei Iancu (@bogdan-iancu), Peter Lemenkov (@lemenkov), Ovidiu Sas (@ovidiusas), Ionut Ionita (@ionutrazvanionita), Walter Doekes (@wdoekes), Christophe Sollet (@csollet), Vlad Paiu (@vladpaiu), Maksym Sobolyev (@sobomax), Anca Vamanu, Andrei Dragus, Sergio Gutierrez, Klaus Darilion, Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Carsten Bock, Ancuta Onofrei, Marcus Hunger, Jeremie Le Hen, Bayan Towfiq, Elena-Ramona Modroiu, Jan Janak (@janakj), Jiri Kuthan (@jiriatipteldotorg).
Documentation Copyrights:
Copyright © 2018 VoIP Embedded, Inc.
Copyright © 2003-2008 Sippy Software, Inc.
Copyright © 2005 Voice Sistem SRL