Contents

Introduction

Research into the operation of SBLA functionality and how it can be implemented. Many existing SIP feature controllers do not support this operation. SLBA is important for many business applications, but is also important for a home (at least the "shared line" functionality). The goal here is to understand how SIP phones implement SLBA and then implement a "front end controller", if you will, that adds SLBA functionality to existing feature servers. I will be using the Pingtel 501 SIP phones and OpenSER to study the problem.

OpenSER recently added a perl module that allows calling perl scripts from SER. I believe that this may be the best way to accomplish the goal.

I realize that this is a bastardized way to add this functionality to a SIP feature server, but.... Well, I'm going to stay away from the religous arguements; this is just a sicence project anyway.

Development Progress

Status	Description
Complete	Compile and Install ser on Debian
Complete	Connect and configure 2 phones
Complete	Register both directly with FoneIP
Complete	Register Alice with ser
Working	Proxy register Alice with FoneIP
	3rd party register Alice@Bob on ser
	Fork incoming call to both registrations
	Configure and study Poylcom's BLA implementation
	Configure and study Polycom's Shared Line implementation
	Implement the BLA state engine using presence module example
	Document findings
	Enhance with operational requirements

• Message Waiting

Need to subscribe for message waiting directly to FoneIP but I am disabling message waiting subscriptions until I get proxy registrations working

Research

Current Approach

• Bridged Line Appearance Draft
• SIP Dialog Event Package
• SIP Service Examples

Reference

• OpenSER
• OpenSER at VoIP-Info
• OpenSER CVS
• OpenSER Documentation Wiki <--- EXCELLENT
• OpenSER Tutorials
• serusers - SER users mail list archives
• serdev - SER development mail list archives
• openser-users - OpenSER users mail list archives
• openser-devel - OpenSER development mail list archives

• IETF sipping WG Drafts
• IETF sip WG Drafts

• Polycom 501 Admin Guide
• Polycom 501 Configuration

Other Implementations

• Asterisk SIP PBX
• Asterisk at VoIP-Info
• Open SIP / SIP Foundary

OpenSER Development

• CVS Access

cd ~
mkdir OpenSER OpenSER/head
cd OpenSER/head
export CVSROOT=:pserver:anonymous@openser.cvs.sourceforge.net:/cvsroot/openser
cvs login
cvs -z3 checkout sip-server
or
cvs -z3 checkout -r rel_1_1_0 sip-server

• Compiling

cd ~/OpenSER/head/sip-server
mv packaging/debian packaging/debian-etch
mv packaging/debian-sarge packaging/debian
chmod a+x packaging/debian/rules
make
make include_modules="perl" modules
make include_modules="perl" deb

Notes:

• Loaded packages: dpatch patchutils mysql-common-4.1 libmysqlclient14 libmysqlclient14-dev zlib1g-dev libexpat1-dev libxml2 libxml2-dev libssl-dev
• Modified packaging/debian/control to remove dependencies for postgresql-dev, libradius-ng-dev, unixodbc-dev, libxmlrpc-c3-dev
• Modified packaging/debian/control to remove references to openser-postgres-module, openser-radius-modules, openser-unixodbc-module, openser-xmlrpc-module
• Modified packaging/debian/rules commenting out explicit lines for postgres, radius, unixodbc, and xmlrpc

Configuring and Running

These directories are debian specific

Config files

• Startup Files

/etc/default/openser
/etc/init.d/openser

• Config Files

/etc/openser/openser.cfg

Starting and Stopping

• Normally in daemon mode (fork=yes)

/etc/init.d/openser start

• For Debugging

/etc/init.d/openser debug

• Check the config file

/usr/sbin/openser -c

Polycom Configuration

Directly registered to FoneIP (bob and alice)

• sip.cfg

voIpProt.local.port=""
voIpProt.server.1.address="216.110.2.134"
voIpProt.server.1.port="5620"
voIpProt.server.1.expires="1800"
dialplan.digitmap="2-911|011xxx.T|011xxx.#|12-9xxxxxxxxx|2-9xxxxxxxxx|*xx|"
voIpProt.SIP.outboundProxy.address="216.110.2.134"
voIpProt.SIP.outboundProxy.port="5620"

• bob.cfg

<sip>
<voIpProt>
<local voIpProt.local.port="5061"/>
</voIpProt>
</sip>
reg.1.displayName="Bob BLA"
reg.1.address="2145501293*99887766"
reg.1.label="1293"
reg.1.auth.userId="2145501293*99887766"
reg.1.auth.password="xxxxxxxx"

msg.mwi.1.subscribe="2145501293*99887766"
msg.mwi.1.callBackMode="Contact"
msg.mwi.1.callBack="8999"

• alice.cfg

<sip>
<voIpProt>
<local voIpProt.local.port="5062"/>
</voIpProt>
</sip>
reg.1.displayName="Alice BLA"
reg.1.address="2145501294*99887766"
reg.1.label="1294"
reg.1.auth.userId="2145501294*99887766"
reg.1.auth.password="xxxxxxxx"

msg.mwi.1.subscribe="2145501294*99887766"
msg.mwi.1.callBackMode="Contact"
msg.mwi.1.callBack="8999"

Proxy registered to FoneIP (alice)

• alice.cfg

<sip>
<voIpProt>
<local voIpProt.local.port="5062"/>
</voIpProt>
<SIP>
<outboundProxy voIpProt.SIP.outboundProxy.address="" voIpProt.SIP.outboundProxy.port=""/>
</SIP>
</sip>
reg.1.displayName="Alice BLA"
reg.1.address="2145501294*99887766"
reg.1.label="1294"
reg.1.type="private"
reg.1.auth.userId="2145501294*99887766"
reg.1.auth.password="xxxxxxxx"
reg.1.server.1.address="192.168.171.208"
reg.1.server.1.port="5620"
reg.1.server.1.expires="1800"
reg.1.outboundProxy.address="192.168.171.208"
reg.1.outboundProxy.port="5620"

msg.mwi.1.subscribe="2145501294*99887766@216.110.2.134:5620"
msg.mwi.1.callBackMode="Contact"
msg.mwi.1.callBack="8999"

OpenSER Config

Notes / Research

• Outbound registration

modparam("uac","credential","xxxxxxx:yyyyy:xxxxxx")
and then add uac_auth like following:
if(!uac_auth()) {log(1,"error for uac_auth\n");}

---

...
#define the credential
modparam("uac","credential","gw_user:gw_realm:gw_passwd")
.....
route
{
	.....
	# set failure route for authentication
	t_on_failure("3")
	# reset flag to mark no authentication yet performed
	resetflag(7);
	# forward to PSTN
	t_relay_to_udp("GW_IP","GW_PORT");
	....
}

failure_route[3]
{
	# authentication reply received?
	if ( t_check_status("401|407") )
	{
		# have we already tried to authenticate?
		if (isflagset(7))
		{
			t_reply("503","Authentication failed");
			break;
		}
		if (uac_auth())
		{
			# mark that auth was performed
			setflag(7);
			# trigger again the failure route
			t_on_failure("3");
			# repeat the request with auth response this time
			append_branch();
			t_relay();
		}
	}
}

• Forking

SER Forking Example

• Complex Example

SIP.edu Cookbook

• Fix to ignore qpop

Comment out the "goto error" section in modules/uac/auth_hdr.c

case QOP_STATE:
                /* TODO - add qop support */
                break;