[SR-Users] Problems with AAR over Rx Interface

Carsten Bock carsten at ng-voice.com
Thu Oct 19 06:15:18 CEST 2017


Hi,

please carefully verify. I've tested the implementation against
various PCRF's (NSN, Ericsson, ZTE, Huawei and others) and we didn't
run into issues. I think they did care about the flow, but I never
really looked into the specs....

There is an undocumented parameter "af_signaling_ip" (shame on me, I
will add that when I'm back from holiday), which can be used to
replace the 127.0.0.1.

Thanks,
Carsten

2017-10-18 21:44 GMT-04:00 Ron McLeod <ron.kamailio at mcleodnet.com>:
> When a LTE handset client attempts to REGISTER with the IMS, an AAR is sent
> from the P-CSCF to the PCRF to establish a dedicated bearer for SIP
> signaling (as well as request notifications for certain access network
> event).  There are a couple of problems with the flow descriptions, and I
> was hoping that someone could confirm that these are actual issues before I
> start working on a fix.
>
> 1. The "in" and "out" directions seem reversed.  "in" corresponds to the
> uplink (UE to network), and "out" corresponds to the downlink (network to
> UE).  In the AAR sent to the PCRF, the "in" description indicates the
> traffic "from" the UE, rather than "to" the UE.  There is a similar problem
> with the "out" description.  A fix would involve reversing "in" and "out".
>
> 2. The IP address and port number for the UE side are correct (in my case
> the UE has been allocated 172.25.152.195, and the client is using port
> 37843), but the network side is specified as IP address 127.0.0.1 and port
> number is the same as the open used by the client (in my case the P-CSCF has
> an IP address of 172.25.152.20 and a port number of 4060).  I see in the
> source code that the P-CSCF address is hard-coded to "127.0.0.1".  A fix
> would involve either using the actual UE-facing IP address and port number
> for the P-CSCF or wildcards.  Another option would be to not try and setup a
> dedicated bearer for SIP signaling, and just use the default bearer (there
> shouldn't be anything else other than signaling-related traffic on the
> default bearer anyway).  The access network HSS would specify that the
> default bearer was created with the appropriate parameters (QCI=5, AM,
> etc.).
>
>
> This is the network message flow:
> 172.25.152.195 -> pcscf.core.ims1.test SIP 999 Request: REGISTER
> sip:provider1.test    (fetch bindings) |
> pcscf.core.ims1.test -> 172.25.152.195 SIP 359 Status: 100 Trying    (0
> bindings) |
> pcscf.core.ims1.test -> pcrf.ims1.test DIAMETER 762 cmd=AARequest(265)
> flags=RP-- appl=3GPP Rx(16777236) h2h=28fe20b1 e2e=fe338ed9
> pcrf.ims1.test -> pcscf.core.ims1.test DIAMETER 198 cmd=AAAnswer(265)
> flags=-P-- appl=3GPP Rx(16777236) h2h=2 e2e=13
> pcscf.core.ims1.test -> 172.25.152.195 SIP 410 Status: 408 Request Timeout
> (0 bindings) |
>
>
> This is the DIAMETER AAR message:
> Diameter Protocol
>     Version: 0x01
>     Length: 696
>     Flags: 0xc0, Request, Proxyable
>     Command Code: 265 AA
>     ApplicationId: 3GPP Rx (16777236)
>     Hop-by-Hop Identifier: 0x28fe20b1
>     End-to-End Identifier: 0xfe338ed9
>     AVP: Session-Id(263) l=40 f=-M- val=pcscf.core.ims1.test;548405219;1
>     AVP: Origin-Host(264) l=28 f=-M- val=pcscf.core.ims1.test
>     AVP: Origin-Realm(296) l=22 f=-M- val=provider1.test
>     AVP: Auth-Application-Id(258) l=12 f=-M- val=3GPP Rx (16777236)
>     AVP: Vendor-Specific-Application-Id(260) l=32 f=-M-
>     AVP: Destination-Realm(283) l=22 f=-M- val=core.ims1.test
>     AVP: Subscription-Id(443) l=52 f=-M-
>     AVP: Media-Component-Description(517) l=304 f=VM- vnd=TGPP
>         AVP Code: 517 Media-Component-Description
>         AVP Flags: 0xc0
>         AVP Length: 304
>         AVP Vendor Id: 3GPP (10415)
>         Media-Component-Description:
> 00000206c0000010000028af0000000100000207c00000bc...
>             AVP: Media-Component-Number(518) l=16 f=VM- vnd=TGPP val=1
>             AVP: Media-Sub-Component(519) l=188 f=VM- vnd=TGPP
>                 AVP Code: 519 Media-Sub-Component
>                 AVP Flags: 0xc0
>                 AVP Length: 188
>                 AVP Vendor Id: 3GPP (10415)
>                 Media-Sub-Component:
> 000001fdc0000010000028af00000001000001fbc0000046...
>                     AVP: Flow-Number(509) l=16 f=VM- vnd=TGPP val=1
>                     AVP: Flow-Description(507) l=70 f=VM- vnd=TGPP
> val=permit out ip from 172.25.152.195 37843 to 127.0.0.1 37843
>                     AVP: Flow-Description(507) l=69 f=VM- vnd=TGPP
> val=permit in ip from 127.0.0.1 37843 to 172.25.152.195 37843
>                     AVP: Flow-Usage(512) l=16 f=VM- vnd=TGPP
> val=AF_SIGNALLING (2)
>             AVP: Media-Type(520) l=16 f=VM- vnd=TGPP val=CONTROL (4)
>             AVP: Codec-Data(524) l=28 f=VM- vnd=TGPP val=downlink\noffer\n
>             AVP: Codec-Data(524) l=27 f=VM- vnd=TGPP val=uplink\nanswer\n
>             AVP: Flow-Status(511) l=16 f=VM- vnd=TGPP val=ENABLED (2)
>     AVP: Specific-Action(513) l=16 f=VM- vnd=TGPP
> val=CHARGING_CORRELATION_EXCHANGE (1)
>     AVP: Specific-Action(513) l=16 f=VM- vnd=TGPP
> val=INDICATION_OF_LOSS_OF_BEARER (2)
>     AVP: Specific-Action(513) l=16 f=VM- vnd=TGPP
> val=INDICATION_OF_RECOVERY_OF_BEARER (3)
>     AVP: Specific-Action(513) l=16 f=VM- vnd=TGPP
> val=INDICATION_OF_RELEASE_OF_BEARER (4)
>     AVP: Specific-Action(513) l=16 f=VM- vnd=TGPP
> val=INDICATION_OF_ESTABLISHMENT_OF_BEARER (now void) (5)
>     AVP: Specific-Action(513) l=16 f=VM- vnd=TGPP val=IP-CAN_CHANGE (6)
>     AVP: Specific-Action(513) l=16 f=VM- vnd=TGPP
> val=ACCESS_NETWORK_INFO_REPORT (12)
>     AVP: Framed-IP-Address(8) l=12 f=-M- val=172.25.152.195
>     AVP: Authorization-Lifetime(291) l=12 f=-M- val=7200
>     AVP: Auth-Grace-Period(276) l=12 f=-M- val=0
>     AVP: Session-Timeout(27) l=12 f=-M- val=7200
>
>
>
>
>
> _______________________________________________
> Kamailio (SER) - Users Mailing List
> sr-users at lists.kamailio.org
> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users



-- 
Carsten Bock
CEO (Geschäftsführer)

ng-voice GmbH
Millerntorplatz 1
20359 Hamburg / Germany

http://www.ng-voice.com
mailto:carsten at ng-voice.com

Office +49 40 5247593-40
Fax +49 40 5247593-99

Sitz der Gesellschaft: Hamburg
Registergericht: Amtsgericht Hamburg, HRB 120189
Geschäftsführer: Carsten Bock
Ust-ID: DE279344284

Hier finden Sie unsere handelsrechtlichen Pflichtangaben:
http://www.ng-voice.com/imprint/



More information about the sr-users mailing list