27 Jul
2017
27 Jul
'17
1:09 p.m.
I'm trying to understand the scenario when `tcp_no_connect` should ever be
set to `no`.
Kamailio comes with `tcp_no_connect=no` by default which means it will try
(and seemingly always fail) to create an outbound tcp connection when a
UAC's tcp connection is lost. This in-turn could start building up the tcp
write queue and can be disastrous at scale.
So why would this setting (`tcp_no_connect=no`) ever be useful?
Thanks
27 Jul
27 Jul
1:30 p.m.
Hello,
do you have tcp_no_connect=no in your config? Because I think the
default value is 0.
It is useful when you have client behind the nat that closed the
connection, but the contact record is still valid in location table.
Cheers,
Daniel
On 27.07.17 13:09, Vik Killa wrote:
I'm trying to understand the scenario when
`tcp_no_connect` should
ever be set to `no`.
Kamailio comes with `tcp_no_connect=no` by default which means it will
try (and seemingly always fail) to create an outbound tcp connection
when a UAC's tcp connection is lost. This in-turn could start building
up the tcp write queue and can be disastrous at scale.
So why would this setting (`tcp_no_connect=no`) ever be useful?
Thanks
_______________________________________________
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sr-users(a)lists.kamailio.org
https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
--
Daniel-Constantin Mierla
www.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com
1:37 p.m.
Ohh, misinterpreted tcp_no_connect=no is tcp_no_connect=0, which is the
default.
My other remark related to user location was for the case of
tcp_no_connect=yes, which I thought is what was meant initially.
Cheers,
Daniel
On 27.07.17 13:30, Daniel-Constantin Mierla wrote:
Hello,
do you have tcp_no_connect=no in your config? Because I think the
default value is 0.
It is useful when you have client behind the nat that closed the
connection, but the contact record is still valid in location table.
Cheers,
Daniel
On 27.07.17 13:09, Vik Killa wrote:
--
Daniel-Constantin Mierla
www.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com
I'm trying to understand the scenario when
`tcp_no_connect` should
ever be set to `no`.
Kamailio comes with `tcp_no_connect=no` by default which means it
will try (and seemingly always fail) to create an outbound tcp
connection when a UAC's tcp connection is lost. This in-turn could
start building up the tcp write queue and can be disastrous at scale.
So why would this setting (`tcp_no_connect=no`) ever be useful?
Thanks
_______________________________________________
Kamailio (SER) - Users Mailing List
sr-users(a)lists.kamailio.org
https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
--
Daniel-Constantin Mierla
www.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com
2:28 p.m.
does it make sense for Kamailio to create a connection if a client behind
NAT has lost the connection? because It will almost always fail.
It does make sense for IPv6 but not in IPv4 networks.
On Thu, Jul 27, 2017 at 7:37 AM, Daniel-Constantin Mierla <miconda(a)gmail.com
wrote:
Ohh, misinterpreted tcp_no_connect=no is
tcp_no_connect=0, which is the
default.
My other remark related to user location was for the case of
tcp_no_connect=yes, which I thought is what was meant initially.
Cheers,
Daniel
On 27.07.17 13:30, Daniel-Constantin Mierla wrote:
Hello,
do you have tcp_no_connect=no in your config? Because I think the default
value is 0.
It is useful when you have client behind the nat that closed the
connection, but the contact record is still valid in location table.
Cheers,
Daniel
On 27.07.17 13:09, Vik Killa wrote:
I'm trying to understand the scenario when `tcp_no_connect` should ever be
set to `no`.
Kamailio comes with `tcp_no_connect=no` by default which means it will try
(and seemingly always fail) to create an outbound tcp connection when a
UAC's tcp connection is lost. This in-turn could start building up the tcp
write queue and can be disastrous at scale.
So why would this setting (`tcp_no_connect=no`) ever be useful?
Thanks
_______________________________________________
Kamailio (SER) - Users Mailing
Listsr-users@lists.kamailio.orghttps://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
--
Daniel-Constantin Mierlawww.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com
--
Daniel-Constantin Mierlawww.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com
3:57 p.m.
thinking more about this, the only time it makes sense (on an IPv4 network)
is if kamailio is operating as a UAC (using uac module)
Or am i misunderstanding something?
my concern here is, it can be a dangerous setting when handling presence
(over TCP) at large scale.
for example if you have 10,000 subscribers and you restart kamailio (drop
all the tcp connections), the tcp write queue will quickly fill up when
your presence module tries sending out NOTIFYs to the UACs on broken tcp
connections. when the tcp write queue fills up, it can create a huge
bottleneck in kamailio and trigger more widespread issues across the system.
I'm looking for clarification on why `tcp_no_connect=0` by default so i can
at least update the doc/wiki on it (and the dangers of it in some setups)
Thanks again!
On Thu, Jul 27, 2017 at 8:28 AM, Vik Killa <vipkilla(a)gmail.com> wrote:
does it make sense for Kamailio to create a connection
if a client behind
NAT has lost the connection? because It will almost always fail.
It does make sense for IPv6 but not in IPv4 networks.
On Thu, Jul 27, 2017 at 7:37 AM, Daniel-Constantin Mierla <
miconda(a)gmail.com> wrote:
Ohh, misinterpreted tcp_no_connect=no is
tcp_no_connect=0, which is the
default.
My other remark related to user location was for the case of
tcp_no_connect=yes, which I thought is what was meant initially.
Cheers,
Daniel
On 27.07.17 13:30, Daniel-Constantin Mierla wrote:
Hello,
do you have tcp_no_connect=no in your config? Because I think the default
value is 0.
It is useful when you have client behind the nat that closed the
connection, but the contact record is still valid in location table.
Cheers,
Daniel
On 27.07.17 13:09, Vik Killa wrote:
I'm trying to understand the scenario when `tcp_no_connect` should ever
be set to `no`.
Kamailio comes with `tcp_no_connect=no` by default which means it will
try (and seemingly always fail) to create an outbound tcp connection when a
UAC's tcp connection is lost. This in-turn could start building up the tcp
write queue and can be disastrous at scale.
So why would this setting (`tcp_no_connect=no`) ever be useful?
Thanks
_______________________________________________
Kamailio (SER) - Users Mailing
Listsr-users@lists.kamailio.orghttps://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
--
Daniel-Constantin Mierlawww.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com
--
Daniel-Constantin Mierlawww.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com
4:37 p.m.
It is responsibility of SIP User Agent to keep connection open to its
SIP Proxy (see outbound rfc). It thus does not make sense for SIP Proxy
to try to open TCP or TLS connection to SIP UA.
I use set_forward_no_connect(); call for that purpose.
-- Juha
4:38 p.m.
Hi,
On Thu, Jul 27, 2017 at 3:57 PM, Vik Killa <vipkilla(a)gmail.com> wrote:
thinking more about this, the only time it makes sense
(on an IPv4 network)
is if kamailio is operating as a UAC (using uac module)
Or am i misunderstanding something?
There are many scenarios, where actively opening a TCP connection to a
peer is desired. Carrier interconnects for example. Or TCP connections
inside a (carrier) network. For those scenarios the default is
suitable.
For a registrar dealing with client connections, you will probably
want to turn creation of TCP sessions off.
Best Regards,
Sebastian
1:32 p.m.
Vik Killa writes:
I'm trying to understand the scenario when
`tcp_no_connect` should ever be
set to `no`.
Kamailio comes with `tcp_no_connect=no` by default which means it will try
(and seemingly always fail) to create an outbound tcp connection when a
UAC's tcp connection is lost. This in-turn could start building up the tcp
write queue and can be disastrous at scale.
So why would this setting (`tcp_no_connect=no`) ever be useful?
For example, if K connects to another K over TCP and the connection does
not exists, it makes sense to create one.
-- Juha
2473
days inactive
2473
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7 comments
4 participants
participants (4)
-
Daniel-Constantin Mierla -
Juha Heinanen -
Sebastian Damm -
Vik Killa