25 Mar
2004
25 Mar
'04
4:52 a.m.
Hi all,
I've configured a local SER on our network, and I met some difficulties with
multiple Contacts.
When UA1 changes IP address, and REGISTER in SER to announce his new IP,
both last and New Contacts are placed in Location table, with different
'expires' values. If UA2 receives last UA1 IP address, and REGISTER with it,
calling UA1 from UA3 when both Contact still available, makes UA2 ringing,
which cause some confusion.
To overcome about this, I'm searching for a way to force SER to delete an
"old Contact" when a Registration is done with same URI and different IP;
That way, only one Contact for one URI is available. I've tried to add
modparam("registrar", "append_branches", 0) in ser.cfg, but in this
case,
Contact with lowest 'expires' parameter is called, and not Contact with
highest one, still causing confusion fo IP calls.
Could anyone tell me how to force a Contact to be deleted in SER location
table, in case of registration with new Contact?
Thanks for your support.
Regards.
Marc
25 Mar
25 Mar
6:45 a.m.
Marc LIVET wrote:
Hi all,
I've configured a local SER on our network, and I met some difficulties with
multiple Contacts.
When UA1 changes IP address, and REGISTER in SER to announce his new IP,
both last and New Contacts are placed in Location table, with different
'expires' values. If UA2 receives last UA1 IP address, and REGISTER with it,
calling UA1 from UA3 when both Contact still available, makes UA2 ringing,
which cause some confusion.
That's a fault of the UA. The UA should un-REGISTER the old contact
before registering a new one.
To overcome about this, I'm searching for a way to
force SER to delete an
"old Contact" when a Registration is done with same URI and different IP;
That way, only one Contact for one URI is available. I've tried to add
modparam("registrar", "append_branches", 0) in ser.cfg, but in this
case,
Contact with lowest 'expires' parameter is called, and not Contact with
highest one, still causing confusion fo IP calls.
The proper parameter is:
modparam("registrar", "desc_time_order", 1)
klaus
7:27 a.m.
--On 25 March 2004 12:45 +0100 Klaus Darilion
<klaus.mailinglists(a)pernau.at> wrote:
Not necessarily. For instance consider UA1 and UA2 are identical UAs on
different DSL lines. They get dynamic IP. The DSLAM reboots. Lines come
back up slowly. If ser gets a valid register request for UA1, it seems
to me it should remove all trace of the old IP address ASAP, as "I am
here" rather implies "I am not there (where there != here)".
Alex
I've
configured a local SER on our network, and I met some difficulties
with multiple Contacts.
When UA1 changes IP address, and REGISTER in SER to announce his new IP,
both last and New Contacts are placed in Location table, with different
'expires' values. If UA2 receives last UA1 IP address, and REGISTER with
it, calling UA1 from UA3 when both Contact still available, makes UA2
ringing, which cause some confusion.
That's a fault of the UA. The UA should un-REGISTER the old contact
before registering a new one. 
8:40 a.m.
At 01:27 PM 3/25/2004, Alex Bligh wrote:
--On 25 March 2004 12:45 +0100 Klaus Darilion
<klaus.mailinglists(a)pernau.at> wrote:
Not necessarily. For instance consider UA1 and UA2 are identical UAs on
different DSL lines. They get dynamic IP. The DSLAM reboots. Lines come
back up slowly. If ser gets a valid register request for UA1, it seems
to me it should remove all trace of the old IP address ASAP, as "I am
here" rather implies "I am not there (where there != here)".
How would you like to distinguish a parallel registration from from
reregistration behind a changed IP address?
-jiri
I've
configured a local SER on our network, and I met some difficulties
with multiple Contacts.
When UA1 changes IP address, and REGISTER in SER to announce his new IP,
both last and New Contacts are placed in Location table, with different
'expires' values. If UA2 receives last UA1 IP address, and REGISTER with
it, calling UA1 from UA3 when both Contact still available, makes UA2
ringing, which cause some confusion.
That's a fault of the UA. The UA should un-REGISTER the old contact
before registering a new one.
26 Mar
26 Mar
6:23 p.m.
--On 25 March 2004 14:40 +0100 Jiri Kuthan <jiri(a)iptel.org> wrote:
May be I am missing the point, but on an identical username registering
in two places, in my application at least, I'd like only the last to
count. If what you are saying is that you want to be able to support
multiple simultaneous registrations of the same user at different IP
addresses, that's fine, but I would guess that is probably not the
most common application.
[note I did not suggest that a second registration with the same IP
address should overwrite the previous u/n at that IP address; I meant
the old IP address entry for UA1 should be erased, not that the old
UA entry (UA2)s against the IP should be erased]
Alex
Not
necessarily. For instance consider UA1 and UA2 are identical UAs on
different DSL lines. They get dynamic IP. The DSLAM reboots. Lines come
back up slowly. If ser gets a valid register request for UA1, it seems
to me it should remove all trace of the old IP address ASAP, as "I am
here" rather implies "I am not there (where there != here)".
How would you like to distinguish a parallel registration from from
reregistration behind a changed IP address?
27 Mar
27 Mar
3:53 a.m.
At 12:23 AM 3/27/2004, Alex Bligh wrote:
--On 25 March 2004 14:40 +0100 Jiri Kuthan
<jiri(a)iptel.org> wrote:
May be I am missing the point, but on an identical username registering
in two places, in my application at least, I'd like only the last to
count.
If what you are saying is that you want to be able to support
multiple simultaneous registrations of the same user at different IP
addresses, that's fine, but I would guess that is probably not the
most common application.
My opinion is that multiple registrations are a feature and they also
handle some change-of-IP-address situations more robustly. I don't
think that there are many real problems which can be solved by single
registration.
Anyhow, in case you think it helps you I'm very happy to find the
piece of information in our documentation for you. Here it is
http://www.iptel.org/ser/doc/seruser/seruser.html#AEN996
-jiri
Not
necessarily. For instance consider UA1 and UA2 are identical UAs on
different DSL lines. They get dynamic IP. The DSLAM reboots. Lines come
back up slowly. If ser gets a valid register request for UA1, it seems
to me it should remove all trace of the old IP address ASAP, as "I am
here" rather implies "I am not there (where there != here)".
How would you like to distinguish a parallel registration from from
reregistration behind a changed IP address?
9:07 a.m.
Jiri,
--On 27 March 2004 09:53 +0100 Jiri Kuthan <jiri(a)iptel.org> wrote:
Anyhow, in case you think it helps you I'm very
happy to find the
piece of information in our documentation for you. Here it is
http://www.iptel.org/ser/doc/seruser/seruser.html#AEN996
Thanks for that. I shall learn to read before writing...
Alex
2:58 a.m.
Jiri Kuthan wrote:
How would you like to distinguish a parallel
registration from from
reregistration behind a changed IP address?
Therefore we would need some unique UA id which is saved with the
location info - e.g. the MAC address plus the applications name (of
course this also will cause troubles if I start the same application two
times simultaneously at the same host).
regards,
klaus
25 Mar
25 Mar
9:41 a.m.
Alex Bligh wrote:
--On 25 March 2004 12:45 +0100 Klaus Darilion
<klaus.mailinglists(a)pernau.at> wrote:
Not necessarily. For instance consider UA1 and UA2 are identical UAs on
different DSL lines. They get dynamic IP. The DSLAM reboots. Lines come
back up slowly. If ser gets a valid register request for UA1, it seems
to me it should remove all trace of the old IP address ASAP, as "I am
here" rather implies "I am not there (where there != here)".
It depends - if I have a SIP phone on my desk and a softphone on my
notebook, booth should be registered and reachable.
klaus
I've
configured a local SER on our network, and I met some difficulties
with multiple Contacts.
When UA1 changes IP address, and REGISTER in SER to announce his new IP,
both last and New Contacts are placed in Location table, with different
'expires' values. If UA2 receives last UA1 IP address, and REGISTER with
it, calling UA1 from UA3 when both Contact still available, makes UA2
ringing, which cause some confusion.
That's a fault of the UA. The UA should un-REGISTER the old contact
before registering a new one. 
3:04 p.m.
On Thu, 25 Mar 2004, Klaus Darilion wrote:
...
That's a fault of the UA. The UA should
un-REGISTER the old contact
before registering a new one.
...
Pretty unlikely that a hard phone is going to be able to un-REGISTER. I
should be able to unplug my hardphone at the office and take it home, and
expect everything to work. But if someone at the office plugs in a new
phone, they could get my hardphones old IP. Are there hard phones that
have an Un-Register key, so I can explicitly un-register before
unplugging?
Tom
26 Mar
26 Mar
7:47 a.m.
I was a little bit too fast with my answer. In most cases the UA is not
guilty, e.g. if I reset the phone, or if the phone is behind NAT (the IP
of the device is always the same, eg. 192.168.0.2, but the pulic IP
changes).
The problem that someones else device may use my old IP address and
receives my calls (until the contact expires) can be solved using random
ports for SIP instead of the standard port (like Windows MEssenger
does). This is IMHO a good solution to prevent attacks - imagine a tool
(e.g. a virus which will act also from infected hosts in the LAN) which
sends INVITEs to random IP addresses port 5060 - I'm sure a lot of
phones in the offices will begin ringing.
Another solution would be to do not accept every calls, but only with
the correct request-URI, e.g. klaus.darilion@myip will be accepted, bot
myneighbors.name@myip will not be accapted. But the user agent should
only verify the username as the IP address in the request-uri will be
changed if you are using nathelper to traverse NATs.
regards,
Klaus
Tom wrote:
On Thu, 25 Mar 2004, Klaus Darilion wrote:
...
That's a fault of the UA. The UA should
un-REGISTER the old contact
before registering a new one.
...
Pretty unlikely that a hard phone is going to be able to un-REGISTER. I
should be able to unplug my hardphone at the office and take it home, and
expect everything to work. But if someone at the office plugs in a new
phone, they could get my hardphones old IP. Are there hard phones that
have an Un-Register key, so I can explicitly un-register before
unplugging?
Tom
7405
days inactive
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days old
10 comments
5 participants
participants (5)
-
Alex Bligh -
Jiri Kuthan -
Klaus Darilion -
Marc LIVET -
Tom