Re: [Devel] [Users] nathelper/rtpproxy when both SIP UA are behind same NAT

Opps i made a mistake, instead of "avp_write" you need to use "avp_printf" to store the pseudo variable into an AVP and when you are doing the comparison with avp_check you need an alias defined for the second AVP otherwise you might end up comparing the AVP with a literal value modparam( "avpops", "avp_aliases", "dest_ip=i:401" ) avp_printf("i:400", "$si"); avp_printf("i:401", "$rd"); if ( avp_check("i:400", "eq/$dest_ip/g") ) { xlog("L_INFO", "\"$si\" == \"$rd\" "); } Norman Brandinger wrote: >I agree that the solution that was presented is BAD for the reasons >stated by both of us and probably more :) > >Perhaps using $Ri after the successful lookup() and comparing it to >the $src_ip AVP would work. > >The problem was trying to compare a pseudo variable with an AVP. > > >The doc <snipped below> does not state that pseudo variables can be >used by avp_write(). > >Pseudo-variables can be used with following modules of OpenSER: > >* avpops - function “avp_printf()” >* xlog - functions “xlog()” and “xdbg()” > >I did try to use avp_write() to save a pseudo variable to an AVP but >was unsuccessful. > >Do you have an example of writing a pseudo variable to an AVP ? > >Regards, >Norm > > > >Tavis P wrote: > > > > > > >>Another, more lightweight solution, is: >> >>After a successful lookup(location) you can compare the received IP >>address ($si) with the destination domain/ip address returned from >>the >>"lookup" function call ($rd), i think these two pieces of information >>are reliable for this purpose >> >>This way you don't have to make extra database calls to determine >>locality >> >>Also if you want to compare pseudo variables you can first write >>them to >>an AVP using "avp_write" and then you can make use of "avp_check" >>with >>data sourced from a pseudo variable >> >>Norman Brandinger wrote: >> >> >> >> >> >> >> >> >>>I have looked into the problem related to saving saving resources by >>>not calling rtpproxy or mediaproxy when both the caller and >>>callee are >>>behind the same NAT. >>> >>>This topic has been discussed many times however, there have been no >>>"working" examples, or even partial examples posted (that I'm aware >>>of). >>> >>>Below is a solution to the problem, but is a BAD hack at best. >>> >>>This solution is BAD because AVP's are added to the usr_preferences >>>table during the registration process, but there is no notification >>>that a registration has expired and is no longer valid. A cron job >>>could be run periodically to delete all received_ip AVP's with no >>>matching entry in the location table, but this is another hack to >>>fix >>>the first hack. >>> >>>The solution is BAD because a database calls must be made to save >>>the >>>received_ip address into an AVP, then another database call must be >>>made to reload the value just so that it can be tested against the >>>caller's $src_ip. A pseudo variable $Ri already exists that >>>contains >>>the value we use in received_ip, but I have not been able to find a >>>way for avp_check() to use $Ri. >>> >>>The solution is BAD because it will fail when the SIP device(s) are >>>behind more than a single NAT router. I believe this is not an >>>issue >>>for 95% of the users and 99% of the small office or home users. >>> >>>I think that a better solution would be to enhance avp_check() to >>>accept pseudo variables for the "value" parameter. This would >>>remove >>>the need for any database calls. >>> >>>I'm cross-posting this response to the developers list to bring this >>>to their attention and ask for suggestions (it's possible that I've >>>totally missed something). If a decision is made to open the avpops >>>module to pseudo variables (other than just avp_print()), I would >>>suggest the following be looked at: >>> >>>avp_check() the value parm should accept pseudo variables >>>avp_write() the value parm should accept pseudo variables >>>avp_pushto() the name parameter should accept pseudo variables >>>avp_op() the value parameter should accept pseudo variables >>> >>>Regards, >>>Norm >>> >>> >>>1) During REGISTER processing, place the following code. I would >>>suggest that you put the code "after" all authentication checks and >>>"after" the save("location") statement. >>> >>># Delete any previously saved IP addressess from the user. >>>avp_db_delete("$from/username","s:received_ip"); >>> >>># Save the source IP address of the user into an AVP called >>>received_ip. >>># The saved IP address should be the public address of the NAT >>>router. >>>avp_write("$src_ip", "s:received_ip"); >>> >>># Save the AVP received_ip into the usr_preferences tables >>>associated >>>with the user that just registered >>>avp_db_store("$from/username","s:received_ip"); >>> >>>2) During INVITE processing (or wherever you make the decision to >>>use >>>or not use rtpproxy / mediaproxy) , place the following code. >>> >>> >>>#--------------------------------------------------------------------------- >>> >>> >>> >>># Are the caller and callee behind the same NAT ? >>> >>>#--------------------------------------------------------------------------- >>> >>> >>> >>>avp_db_load("$to/username", "s:received_ip"); >>>if (avp_check("s:received_ip", "eq/$src_ip")) { >>> setflag(CALLER_AND_CALLEE_ ARE_BEHIND_THE_SAME_NAT); >>>}; >>> >>> >>> >>>_______________________________________________ >>>Devel mailing list &gt;&gt;&gt;Devel(a)openser.org >>>http://openser.org/cgi-bin/mailman/listinfo/devel >>> >>> >>> >>> >>> >>> >> >> >> >> >> > > > > _______________________________________________ Users mailing list Users(a)openser.org http://openser.org/cgi-bin/mailman/listinfo/users