Subject: [Megaco] Validating RTP stream

From: Shobhit Bansal <[email-masked]>
Date: Wed, 16 Aug 2006 04:57:59 +0530

Hi all,

I have some basic questions regarding the media streams.

Lets say we have an ephemeral termination with valid local descriptor (ip addr 192.168.1.100, port 5004) and remote descriptor (ip addr 10.10.4.5, port 6010).

1> I understand that remote descriptor means that the RTP going out will have the destination ip address as 10.10.4.5 and port 6010 but can we assume that the RTP stream that will be coming from the other end with have the source ip as 10.10.4.5 and port 6010 ?

2> If not, is there a parameter by which we can confirm that the RTP stream is valid or not. Consider a scenario where a termination is malfunctioning and keeps on generating RTP stream towards this ephemeral. How can we reject this RTP stream ?

Thanks and regards

Shobhit Bansal

Technical Leader

Flextronics Software Systems

*****FSS-Unclassified *****" DISCLAIMER: This message is proprietary to Flextronics Software Systems Limited (FSS) and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. FSS accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."

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From: [email-masked]
Date: Wed, 16 Aug 2006 09:43:01 +0200

Shobhit:

>1:
Depends on symmetrical or asymmetrical RTP/IP.
You cannot per se suppose symmetry.

>2:
via "source address/port filtering"

See e.g.
      Draft H.248 Series Supp. X RTPXtalk (H.248.43 (ex. H.248.RTPXtalk))
      Guidelines for Resource Management of Resources for H.248 RTP
      Terminations

      Note: this Supplement is particularly discussing "... malfunctioning
      and keeps on generating RTP stream ...", called "RTP crosstalk".

      ETSI H.248 gm package in ETSI TS 102 333
      Work item on Draft H.248.gmgc

- Albrecht

                      Shobhit Bansal                                                                                                              
                      <shobhit.bansal@flextronicsso         To:      [email-masked]                                                              
                      ftware.com>                           cc:                                                                                   
                                                            Subject: [Megaco] Validating RTP stream                                               
                      16.08.2006 01:27                                                                                                            

Hi all,

Lets say we have an ephemeral termination with valid local descriptor (ip
addr 192.168.1.100, port 5004) and remote descriptor (ip addr 10.10.4.5,
port 6010).

1> I understand that remote descriptor means that the RTP going out will
have the destination ip address as 10.10.4.5 and port 6010 but can we
assume that the RTP stream that will be coming from the other end with have
the source ip as 10.10.4.5 and port 6010 ?

2> If not, is there a parameter by which we can confirm that the RTP stream
is valid or not. Consider a scenario where a termination is malfunctioning
and keeps on generating RTP stream towards this ephemeral. How can we
reject this RTP stream ?

Thanks and regards
Shobhit Bansal
Technical Leader

*****FSS-Unclassified *****" DISCLAIMER: This message is proprietary to
Flextronics Software Systems Limited (FSS) and is intended solely for the
use of the individual to whom it is addressed. It may contain privileged or
confidential information and should not be circulated or used for any
purpose other than for what it is intended. If you have received this
message in error, please notify the originator immediately. If you are not
the intended recipient, you are notified that you are strictly prohibited
from using, copying, altering, or disclosing the contents of this message.
FSS accepts no responsibility for loss or damage arising from the use of
the information transmitted by this email including damage from virus."
_______________________________________________
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---

From: "B Venkat S.R Swamy" <[email-masked]>
Date: Wed, 16 Aug 2006 13:55:02 +0530

Hi

Regarding "Source address/port filtering", how does Session controller know the RTP

source address/port to be used for filtering, since Remote Descriptor only specifies what port remote is listening.

Is it a provisioning data or there is some other signalling mechansim.

regards

B Venkat S.R Swamy

Senior Technical Leader

Phone: +91-124- 4176213

Fax: +91-124-4300247

web: www.flextronicssoftware.com

[email-masked]

[email-masked]

08/16/2006 01:13 PM

To

Shobhit Bansal/HSS@HSS

cc

[email-masked]

Subject

RTP crosstalk; Re: [Megaco] Validating RTP stream

See e.g.

Terminations

- Albrecht

Shobhit Bansal

ftware.com>                           cc:

16.08.2006 01:27

Hi all,

port 6010).

reject this RTP stream ?

Thanks and regards

Shobhit Bansal

Technical Leader

Megaco mailing list

[email-masked]

Megaco mailing list

[email-masked]

*********************** FSS-Restricted ***********************

"DISCLAIMER: This message is proprietary to Flextronics Software

Systems Limited (FSS) and is intended solely for the use of the

individual to whom it is addressed. It may contain privileged or

confidential information and should not be circulated or used for

any purpose other than for what it is intended. If you have received

this message in error, please notify the originator immediately.

If you are not the intended recipient, you are notified that you are

strictly prohibited from using, copying, altering, or disclosing

the contents of this message. FSS accepts no responsibility for

loss or damage arising from the use of the information transmitted

by this email including damage from virus."

---

From: [email-masked]
Date: Wed, 16 Aug 2006 13:12:21 +0200

In my opinion:

a) provisioning => Not possible.

b) implicit "signalling" by 'symmetry assumptions' => possible
   [Note: this is then an underlying operations requirement for all RTP
equipment in such a RTP domain.]

c) explicit signalling, e.g. via gm package (gm properties saf, sam, spf,
spr) => possible
   [Note: implies of course that the MGC has access on such information,
from call/session control signalling; or from a database in case of "static
configurations"]

- Albrecht

PS
Venkat: if you've still concerns/question, then I would appreciate
contributions against Draft ITU-T H.Sup.RTPXtalk.

                      "B Venkat S.R Swamy"                                                                                                 
                      <b.swamy@flextronicsso         To:      Albrecht SCHWARZ/DE/ALCATEL@ALCATEL                                          
                      ftware.com>                    cc:      [email-masked]                                                              
                                                     Subject: Re: RTP crosstalk; Re: [Megaco] Validating RTP stream                        
                      16.08.2006 10:25                                                                                                     

Hi

Regarding "Source address/port filtering", how does Session controller know
the RTP
source address/port to be used for filtering, since Remote Descriptor only
specifies what port remote is listening.
Is it a provisioning data or there is some other signalling mechansim.

regards
B Venkat S.R Swamy
Senior Technical Leader
Flextronics Software Systems
Phone: +91-124- 4176213
Fax: +91-124-4300247
web: www.flextronicssoftware.com
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                                               RTP crosstalk; Re: [Megaco] 
                                               Validating RTP stream       

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See e.g.

- Albrecht

                     Shobhit Bansal

                     <shobhit.bansal@flextronicsso         To:
[email-masked]

                     ftware.com>                           cc:

                                                           Subject:
[Megaco] Validating RTP stream

                     16.08.2006 01:27

Hi all,

Thanks and regards
Shobhit Bansal
Technical Leader