RTMMoIP RTMMoIP

Alfredo Terzoli / Mosiuoa TsietsiAlfredo Terzoli / Mosiuoa Tsietsi

PLANPLAN

• Defining the softswitchDefining the softswitch

• An example softswitch: iLangaAn example softswitch: iLanga

• The core of iLanga: AsteriskThe core of iLanga: Asterisk

SoftswitcSoftswitch in h in action!action!

As an aside, a bit of SS7 As an aside, a bit of SS7 terminologyterminology

SSP: Service Switching Point SSP: Service Switching Point (also called ‘central (also called ‘central office switch’) office switch’)

SCP: Service Control Point SCP: Service Control Point

STP: Signal Transfer Point STP: Signal Transfer Point

Softswitch: a simple Softswitch: a simple definitiondefinition

• ‘‘Switching’ in classic telephony is the Switching’ in classic telephony is the connection of one telephone user to another connection of one telephone user to another

• Initially done manually, it has become more Initially done manually, it has become more and more complex and sophisticatedand more complex and sophisticated

• The ‘switch’, the network element doing the The ‘switch’, the network element doing the switching, has become over the years the switching, has become over the years the cornerstone of telephony networkscornerstone of telephony networks

• If the job of switching is done in If the job of switching is done in software, uses packet networks and software, uses packet networks and support multiple protocols, the switch support multiple protocols, the switch is called SOFTSWITCHis called SOFTSWITCH

Softswitch: functionsSoftswitch: functions

• ““According to the International Softswitch According to the International Softswitch Consortium, a softswitch should be able to Consortium, a softswitch should be able to – (1) control connection services for a media (1) control connection services for a media

gateway and/or native IP endpoints gateway and/or native IP endpoints – (2) select processes that can be applied to a call (2) select processes that can be applied to a call – (3) provide routing for a call within the network (3) provide routing for a call within the network

based on signaling and customer database based on signaling and customer database information information

– (4) transfer control of the call to another (4) transfer control of the call to another network element and network element and

– (5) interface to and support management (5) interface to and support management functions such as provisioning, fault, billing” functions such as provisioning, fault, billing”

((http://www.pcmag.com/encyclopedia_term/http://www.pcmag.com/encyclopedia_term/0,2542,t=softswitch&i=51659,00.asp )0,2542,t=softswitch&i=51659,00.asp )

Softswitch: metapointsSoftswitch: metapoints

• Essentially, the softswitch is needed to Essentially, the softswitch is needed to make the new network ‘recognizable’ make the new network ‘recognizable’ by Telco operatorsby Telco operators

• Less important from the point of view Less important from the point of view of people with data networking of people with data networking background (Internet), but still usefulbackground (Internet), but still useful

• Not a ‘hard and fast’ definitionNot a ‘hard and fast’ definition• Term very much used in the industry Term very much used in the industry

currentlycurrently

Transformations (still Transformations (still metapoints…)metapoints…)

• International Softswitch Consortium International Softswitch Consortium (http://www.softswitch.org) (http://www.softswitch.org)

• International Packet Communication International Packet Communication Consortium (http://www.ipccforum.org) Consortium (http://www.ipccforum.org)

• IMS Forum (http://www.imsforum.org)IMS Forum (http://www.imsforum.org)

• IP Multimedia Subsystem? Check it out at IP Multimedia Subsystem? Check it out at http://en.wikipedia.org/wiki/IP_Multimedia_Subsystemhttp://en.wikipedia.org/wiki/IP_Multimedia_Subsystem

Softswitch: benefitsSoftswitch: benefits

• Flexibility, naturally, as one should Flexibility, naturally, as one should expect from a software artefactexpect from a software artefact

• Generality: every known telephony Generality: every known telephony technology is supposed to be able to technology is supposed to be able to attach with the appropriate adapterattach with the appropriate adapter

• Cost reduction: it might sound Cost reduction: it might sound strange, but it has to do with the very strange, but it has to do with the very expensive Telco traditional expensive Telco traditional equipmentequipment

Softswitch: typical Softswitch: typical architecturearchitecture

• Although strictly not necessary, Although strictly not necessary, softswitches are often decomposed into:softswitches are often decomposed into:– call controlcall control– media transportmedia transport– servicesservices

• The decomposition is often physicalThe decomposition is often physical• Practical example, the Verso system Practical example, the Verso system

downstairs, in the ‘fish-bowl’ next to the downstairs, in the ‘fish-bowl’ next to the entranceentrance

iLanga: a small iLanga: a small softswitchsoftswitch

Asterisk

GnuGK

iLangaproxy

iLanga Core

Legacy PBXBRIPRI

PSTNBRIPRI

SIPIAXH.323MGCP

Local VoIP Endpoints

SER

Internet

Main componentsMain components

• SER, Sip Express Router: SER, Sip Express Router: www.iptel.orgwww.iptel.org

•AsteriskAsterisk: www.asterisk.org: www.asterisk.org

• GnuGK (or OpenH323 Gatekeeper): GnuGK (or OpenH323 Gatekeeper): www.gnugk.org www.gnugk.org

Questions?Questions?