Architecting a cloud based IP Multimedia System (IMS)

Here is an idea of mine that has been slow cooking in my head for more than 1 and a 1/2 year. Finally managed to work its way to IP.com. See link below

The full article is included below

Abstract

This article describes an innovative technique of “cloudifying” the network elements of the IP Multimedia (IMS) framework in order to take advantage of keys benefits of the cloud like elasticity and the utility style pricing. This approach will provide numerous advantages to the Service Provider like better Return-on-Investment(ROI), reduction in capital expenditure and quicker deployment times, besides offering the end customer benefits like the availability of high speed and imaginative IP multimedia services

Introduction

IP Multimedia Systems (IMS) is the architectural framework proposed by 3GPP body to establish and maintain multimedia sessions using an all IP network. IMS is a grand vision that is access network agnostic, uses an all IP backbone to begin, manage and release multimedia sessions. This is done through network elements called Call Session Control Function (CSCFs), Home Subscriber Systems (HSS) and Application Servers (AS). The CSCFs use SDP over SIP protocol to communicate with other CSCFs and the Application Servers (AS’es). The CSCFs also use DIAMETER to talk to the Home Subscriber System (HSS’es).

Session Initiation Protocol (SIP) is used for signaling between the CSCFs to begin, control and release multi-media sessions and Session Description Protocol (SDP) is used to describe the type of media (voice, video or data). DIAMETER is used by the CSCFs to access the HSS. All these protocols work over IP. The use of an all IP core network for both signaling and transmitting bearer media makes the IMS a very prospective candidate for the cloud system.

This article proposes a novel technique of “cloudifying” the network elements of the IMS framework (CSCFs) in order to take advantage of the cloud technology for an all IP network. Essentially this idea proposes deploying the CSCFs (P-CSCF, I-CSCF, S-CSCF, BGCF) over a public cloud. The HSS and AS’es can be deployed over a private cloud for security reasons. The above network elements either use SIP/SDP over IP or DIAMETER over IP. Hence these network elements can be deployed as instances on the servers in the cloud with NIC cards. Note: This does not include the Media Gateway Control Function (MGCF) and the Media Gate Way (MGW) as they require SS7 interfaces. Since IP is used between the servers in the cloud the network elements can setup, maintain and release SIP calls over the servers of the cloud. Hence the IMS framework can be effectively “cloudified” by adopting a hybrid solution of public cloud for the CSCF entities and the private cloud for the HSS’es and AS’es.

This idea enables the deployment of IMS and the ability for the Operator, Equipment Manufacturer and the customer to quickly reap the benefits of the IMS vision while minimizing the risk of such a deployment.

Summary

IP Multimedia Systems (IMS) has been in the wings for some time. There have been several deployments by the major equipment manufacturers, but IMS is simply not happening. The vision of IMS is truly grandiose. IMS envisages an all-IP core with several servers known as Call Session Control Function (CSCF) participating to setup, maintain and release of multi-media call sessions. The multi-media sessions can be any combination of voice, data and video.

In the 3GPP Release 5 Architecture IMS draws an architecture of Proxy CSCF (P-CSCF), Serving CSCF(S-CSCF), Interrogating CSCF(I-CSCF), and Breakout CSCF(BGCF), Media Gateway Control Function (MGCF), Home Subscriber Server(HSS) and Application Servers (AS) acting in concert in setting up, maintaining and release media sessions. The main protocols used in IMS are SIP/SDP for managing media sessions which could be voice, data or video and DIAMETER to the HSS.

IMS is also access agnostic and is capable of handling landline or wireless calls over multiple devices from the mobile, laptop, PDA, smartphones or tablet PCs. The application possibilities of IMS are endless from video calling, live multi-player games to video chatting and mobile handoffs of calls from mobile phones to laptop. Despite the numerous possibilities IMS has not made prime time.

The technology has not turned into a money spinner for Operators. One of the reasons may be that Operators are averse to investing enormous amounts into new technology and turning their network upside down.

The IMS framework uses CSCFs which work in concert to setup, manage and release multi media sessions. This is done by using SDP over SIP for signaling and media description. Another very prevalent protocol used in IMS is DIAMETER. DIAMETER is the protocol that is used for authorizing, authenticating and accounting of subscribers which are maintained in the Home Subscriber System (HSS). All the above protocols namely SDP/SIP and DIAMETER protocols work over IP which makes the entire IMS framework an excellent candidate for deploying on the cloud.

Benefits

There are 6 key benefits that will accrue directly from the above cloud deployment for the IMS. Such a cloud deployment will

i. Obviate the need for upfront costs for the Operator

ii. The elasticity and utility style pricing of the cloud will have multiple benefits for the Service Provider and customer

iii. Provider quicker ROI for the Service Provider by utilizing a innovative business model of revenue-sharing for the Operator and the equipment manufacturer

iv. Make headway in IP Multimedia Systems

v. Enable users of the IMS to avail of high speed and imaginative new services combining voice, data, video and mobility.

vi. The Service Provider can start with a small deployment and grow as the subscriber base and traffic grows in his network

Also, a cloud deployment of the IMS solution has multiple advantages to all the parties involved namely

a) The Equipment manufacturer

b) The Service Provider

c) The customer

A cloud deployment of IMS will serve to break the inertia that Operators have for deploying new architectures in the network.

a) The Equipment manufactures for e.g. the telecommunication organizations that create the software for the CSCFs can license the applications to the Operators based on innovative business model of revenue sharing with the Operator based on usage

b) The Service Provider or the Operator does away with the Capital Expenditure (CAPEX) involved in buying CSCFs along with the hardware. The cost savings can be passed on to the consumers whose video, data or voice calls will be cheaper. Besides, the absence of CAPEX will provide better margins to the operator. A cloud based IMS will also greatly reduce the complexity of dimensioning a core network. Inaccurate dimensioning can result in either over-provisioning or under-provisioning of the network. Utilizing a cloud for deploying the CSCFs, HSS and AS can obviate the need upfront infrastructure expenses for the Operator. As mentioned above the Service Provider can pay the equipment manufactured based on the number of calls or traffic through the system

c) Lastly the customer stands to gain as the IMS vision truly allows for high speed multimedia sessions with complex interactions like multi-party video conferencing, handoffs from mobile to laptop or vice versa. Besides IMS also allows for whiteboarding and multi-player gaming sessions.

Also the elasticity of the cloud can be taken advantage of by the Operator who can start small and automatically scale as the user base grows.

Description

This article describes a method in which the Call Session Control Function (CSCFs) namely the P-CSCF, S-CSCF,I-CSCF and BGCF can be deployed on a public cloud. This is possible because there are no security risks associated with deploying the CSCFs on the public cloud. Moreover the elasticity and the pay per use of the public cloud are excellent attributes for such a cloudifying process. Similarly the HSS’es and AS’es can be deployed on a private cloud. This is required because the HSS and the AS do have security considerations as they hold important subscriber data like the IMS Public User Identity (IMPU) and the IMS Private User Identity (IMPI). However, the Media Gateway Control Function (MGCF) and Media Gateway (MGW) are not included this architecture as these 2 elements require SS7 interfaces

Using the cloud for deployment can bring in the benefits of zero upfront costs, utility style charging based on usage and the ability to grow or shrink elastically as the call traffic expands or shrinks.

This is shown diagrammatically below where all the IMS network elements are deployed on a cloud.

In Fig 1., all the network elements are shown as being part of a cloud.

Fig 1. Cloudifying the IMS architecture.

Detailed description

This idea requires that the IMS solution be “cloudified “i.e. the P-CSCF, I-CSCF, S-CSCF and the BGCF should be deployed on a public cloud. These CSCFs are used to setup, manage and release calls and the information that is used for the call does not pose any security risk. These network elements use SIP for signaling and SDP over SIP for describing the media sessions. The media sessions can be voice, video or data.

However the HSS and AS which contain the Public User Identity (IMPU) and Private User Identity (IMPI) and other important data can be deployed in a private cloud. Hence the IMS solution needs a hybrid solution that uses both the public and private cloud. Besides the proxy SIP servers, Registrars and redirect SIP servers also can be deployed on the public cloud.

The figure Fig 2. below shows how a hybrid cloud solution can be employed for deploying the IMS framework

Fig 2: Utilizing a hybrid cloud solution for deploying the IMS architecture

The call from a user typically originated from a SIP phone and will initially reach the P-CSCF. After passing through several SIP servers it will reach a I-CSCF. The I-CSCF will use DIAMETER to query the HSS for the correct S-CSCF to handle the call. Once the S-CSCF is identified the I-CSCF then signals the S-CSCF to reach a terminating a P-CSCF and finally the end user on his SIP phone. Since the call uses SDP over SIP we can imagine that the call is handled by P-CSCF, I-CSCF, S-CSCF and BGCF instances on the cloud. Each of the CSCFs will have the necessary stacks for communicating to the next CSCF. The CSCF typically use SIP/SDP over TCP or UDP and finally over IP. Moreover query from the I-CSCF or S-CSCF to the HSS will use DIAMTER over UDP/IP. Since IP is the prevalent technology between servers in the cloud communication between CSCFs is possible.

Methodology

The Call Session Control Functions (CSCFs P-CSCF, I-CSCF, S-CSCF, BGCF) typically handle the setup, maintenance and release of SIP sessions. These CSCFs use either SIP/SDP to communicate to other CSCFs, AS’es or SIP proxies or they use DIAMETER to talk to the HSS. SIP/SDP is used over either the TCP or the UDP protocol.

We can view each of the CSCF, HSS or AS as an application capable of managing SIP or DIAMETER sessions. For this these CSCFs need to maintain different protocol stacks towards other network elements. Since these CSCFs are primarily applications which communicate over IP using protocols over it, it makes eminent sense for deploying these CSCFs over the cloud.

The public cloud contains servers in which instances of applications can run in virtual machines (VMs). These instances can communicate to other instances on other servers using IP. In essence the entire IMS framework can be viewed as CSCF instances which communicate to other CSCF instances, HSS or AS over IP. Hence to setup, maintain and release SIP sessions we can view that instances of P-CSCF, I-CSCF, S-CSCF and B-CSCF executed as separate instances on the servers of a public cloud and communicated using the protocol stacks required for the next network element. The protocol stacks for the different network elements is shown below

The CSCF’s namely the P-CSCF, I-CSCF, S-CSCF & the BGCF all have protocol interfaces that use IP. The detailed protocol stacks for each of these network elements are shown below. Since they communicate over IP the servers need to support 100 Base T Network Interface Cards (NIC) and can typically use RJ-45 connector cables, Hence it is obvious that high performance servers which have 100 Base T NIC cards can be used for hosting the instances of the CSCFs (P-CSCF, I-CSCF, S-CSCF and BGCF). Similarly the private cloud can host the HSS which uses DIAMETER/TCP-SCTP/IP and AS uses SDP/SIP/UDP/IP. Hence these can be deployed on the private cloud.

Network Elements on the Public Cloud

The following network elements will be on the public cloud

a) P-CSCF b) I-CSCF c) S-CSCF d) BGCF

The interfaces of each of the above CSCFs are shown below

a) Proxy CSCF (P-CSCF) interface

As can be seen from above all the interfaces (Gm, Gq, Go and Mw) of the P-CSCF are either UDP/IP or SCTP/TCP/IP.

b) Interrogating CSCF(I- CSCF) interface

As can be seen from above all the interfaces (Cx, Mm and Mw) of the I-CSCF are either UDP/IP or SCTP/TCP/IP.

c) Serving CSCF (S-CSCF) interfaces

The interfaces of the S-CSCF (Mw, Mg, Mi, Mm, ISC and Cx) are all either UDP/IP or SCTP/TCP/IP

d) Breakout CSCF (BGCF) interface

The interfaces of the BGCF (Mi, Mj, Mk) are all UDP/IP.

Network elements on the private cloud

The following network elements will be on the private cloud

a) HSS b) AS

a) Home Subscriber Service (HSS) interface

The HSS interface (Cx) is DIAMETER/SCTP/TCP over IP.

b) Application Server (AS) Interface

The AS interface ISC is SDP/SIP/UDP over IP.

As can be seen the interfaces the different network elements have towards other elements are over either UDP/IP or TCP/IP.

Hence we can readily see that a cloud deployment of the IMS framework is feasible.

Conclusion

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Thus it can be seen that a cloud based IMS deployment is feasible given the IP interface of the CSCFs, HSS and AS. Key features of the cloud like elasticity and utility style charging will be make the service attractive to the Service providers. A cloud based IMS deployment is truly a great combination for all parties involved namely the subscriber, the Operator and the equipment manufactures. A cloud based deployment will allow the Operator to start with a small customer base and grow as the service becomes popular. Besides the irresistibility of IMS’ high speed data and video applications are bound to capture the subscribers imagination while proving a lot cheaper.

Also see my post on “Envisioning a Software Defined Ip Multimedia System (SD-IMS)”

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Accelerating growth through M-Banking & M-Health

While only roughly about 5% of the population has access to computers, more than 50% of the world population has mobile phones. Mobile phones have become cheaper and are more ubiquitous these days. Hence given the penetration of mobile phones it makes sense to use them for improving the lives of those in emerging economies. Two such technologies which hold enormous potential are m-banking and m-health described below.

M-banking: Financial services, a key driver for economic growth, is either negligible or completely absent in remote rural areas. Regular banking services are unviable in these areas. The small deposits and loans held by the rural poor make it unprofitable for traditional banks to operate in these areas through traditional delivery methods. In these areas m-banking is truly a god send.

M-Banking refers to financial services offered by Service Providers to the unbanked poor in rural areas. The people in these villages can purchase either pre-paid or post-paid units from the Operator. They can then use these units to pay for goods and services. M-Banking offers a safe and secure method to the unbanked poor for sending and receiving payments through SMS’es. To make m-banking a reality, requires the coming together of the 3 major players namely the Service Provider, the Application developer and the financial institution which can regulate and disburse units of money.

A recent report by McKinsey with GSMA in 147 countries shows that more than 1.7 billion people in emerging economies will have a mobile phone without access to banking services. The McKinsey reports also states that by 2012 the opportunity in m-banking would generate $5 billion annually in direct revenue from financial transactions and $3 billion in indirect revenue through reduced customer churn and higher ARPU for traditional voice and SMS services.

Some examples of success are M-Pesa of Kenya, Wizzit in South Africa and Globe in Philippines. M-banking provides a 24×7 service in the village and does not require any complicated infrastructure. One could imagine services where the unbanked poor could receive instant payment for the farm produce, could save money on a regular basis and pay for electricity bills instantaneously through SMS. This will increase both the sense of security and personal well being.

M-banking provides for tremendous socio-economic growth in the villages. With the increasing penetration and the ubiquity of mobile phones m-banking represents a sure-shot way of ensuring all round economic transformation in the villages. M-banking helps in reducing risk and brings true convenience to financial transactions. However, appropriate authentication and authorization procedures should be used.

Mobile banking does not need expensive infrastructure that is required of banks, the network of ATMs for depositing and withdrawal of money. M-banking is convenient, secure, easy to use and can be quickly deployed. While the Service Providers are the facilitators of m-banking, it is the financial institutions that will regulate and provide banking facility to the unbanked poor.

Hence m-banking is a complete win-win situation for the all the players involved namely the CSPs, the financial institutions and the unbanked poor. Besides providing convenience, m-banking will be a key driver for all round economic growth in the villages.

M-Health: Another companion technology which has enormous potential in emerging markets is m-health. M-health relates to the provision of health services in rural areas where there is an acute shortage of qualified health workers. In these areas the use of mobile communication can help in addressing key health needs of the poor, thanks to the explosive growth of mobile phones in these areas.

Some of the key benefits of m-health is the ability to spread timely health related information and diagnoses to the health workers in the villages enabling the ability to quickly track and contain the spread of diseases and epidemics. Other applications include remote data collection and monitoring of health related issues.

Recent estimates indicate that half of the population in remote areas will have a mobile phone by 2012. This provides inmates in even the remote villages’ instant access to the important health related information’s-health along with m-banking can allow Health organizations to transfer funds which the needy can use for performing health checkups.

Like m-banking SMS is a key enabler of m-health. SMS’es can be sent to educate and spread awareness of diseases, transfer funds and for informing the availability of health services. Health workers can mobile phones or PDAs to collect and send disease related data.

M-health also provides a unique opportunity for Service Providers, Health institutions, insurance companies and the patients themselves.

Conclusion: With the increasing penetration of mobiles both m-banking and m-health are particularly relevant today. Both these technologies are capable of not only transforming the economic landscape but also providing the CSPs, financial and health institutions with a sound business and strategic advantage.

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The Future of Telecom

Published in Voice & Data – Bright Future

Introduction: The close of the 20^th century will long be remembered for one thing. The dotcom bust followed by the downward spiral of many major telecom and technology companies. For those who believe in the theory of the 12 year economic cycle this downturn is right about to end and we should see good times soon. Even otherwise there is good news for those in the telecom domain. We could shortly be witness to golden years ahead. There are many signs that seem to indicate that the telecom industry is on the verge of many major breakthroughs. Technologies like LTE, IMS, smartphones, cloud computing point to interesting times ahead. In fact telecom is at a inflexion point when the fortunes seem to be pointed northward. This article looks at some of the promising technologies which are going to bring back the sunshine to telecom.

3G Technologies –Better Quality of Experience (QoE): The auction of the 3G spectrum ended after 131 days of hectic bidding for this cutting edge telecom technology. 3G promises a whole new customer experience backed by extremely high data speeds. 3G promises download speed of up to 2 Mbps for stationary subscribers and 384 Kbps for moving subscribers. It is very clear that such high data speeds will inspire a host of new and exciting applications. Applications that span location based services (LBS), m-Commerce and NFC communications will be simply be irresistible to the users. Moreover the ability to watch video clips or live action on mobile TV or on laptops enabled with 3G dongles will have a lot of takers for 3G technology. App stores for 3G are bound to do a roaring business as 3G takes off in India.

Smartphones – The game changers: In the last decade or so in the telecom industry no other invention has had such a disruptive effect in the telecom domain as smartphones. Smartphones like the IPhone, Droid or Nexus One have changed the rules of the game. The impact of smartphone has been so huge that it actually spawned an entire industry of developers who developed applications for smartphones, content developers and app stores. The irresistible appeal of smartphones is the ease of use and the ability to browse the net as though they were using a normal data connection. Users can watch youtube clips, play games or chat on the Smartphone.

IP Multimedia Systems (IMS) – Digital Convergence: IP Multimedia System (IMS) , based on 3GPP’s Release 5 Specification in 2005, has been in the wings for quite some time. The IMS envisions an access agnostic telecommunication architecture that will use an all-IP Core for the transport of medium be it voice, data or video. IMS uses SIP protocol for signaling between network elements and SDP for exchanging media between applications. The IMS architecture promises a whole slew of exciting application ranging from high quality video conference, high speed data access, white boarding or real time interactive gaining. IMS represents a true convergence of the telecom wireless concepts with the data communication protocols. The types of services that are possible with IMS will be only limited by imagination. With the entry of smartphones and tablet PCs, IMS is a technology that is waiting to happen and will soon become prime time

Long Term Evolution (LTE) – Blazing Speeds: Already there are upward of 5 billion mobile devices and a report from Cisco states that the total data navigating the net will exceed ½ a zettabyte (10²¹) by the year 2013. The exponential growth of data and the need to provide even higher Quality of Experience (QoE) led to the development of the LTE. LTE is considered 4G technology. LTE promises speeds anywhere between to 56 Mbps to 100 Mbps to users enabling unheard of speeds and applications. What makes LTE so attractive is that it promises better spectral efficiency and lower cost per bit than 3G networks. The competing technology for LTE is WIMAX which is also considered as 4G. But LTE has a better evolution path from 3G networks as opposed to WiMAX, While LTE is a packet only network there are sound strategies for handling voice traffic with LTE. The standards body 3GPP offers two options for handling voice. The first is the Circuit switched (CS) fallback to 2G/3G network. In this scenario data access will be through the packet network of LTE while voice calls will use legacy 2G/3G voice networks. The other alternative is the switch voice traffic to the IMS network with its all-IP Core. This method is supported by the One Voice initiative of many major telecom companies and accepted by GSMA. This strategy for handling voice through an IMS network is known as VoLTE (Voice over LTE)

Internet of Things- Towards a connected World: “The Internet of Things” visualizes a highly interconnected world made of tiny passive or intelligent devices that connect to large databases and to the internet. This technology promises to transform the network from a dumb-bit pipe to a truly “computing” network. The Internet of Things or M2M (machine-to-machine) envisages an anytime, anywhere, anyone, anything network. The devices in this M2M network will be made up of passive elements, sensors and intelligent devices that communicate with the network. The devices will be capable of sensing, identifying and responding to changes in the immediate environment. Radio Frequency Identification (RFIDs) is one of the early and key enabler of this technology. The uses for this technology range from warning when the structural integrity of bridges is compromised to implantable devices in heart patients warning doctors of possible heart attacks. The impact of the Internet of Things will be far-reaching. There are numerous applications for this technology. In fact, ubiquitous computing or the Internet of Things allows us to distribute processing power and intelligence throughout the network into a kind of ambient intelligence spread across the network. This technology promises to blur the lines between science fiction and reality.

App Stores – The final verdict: The success of App Stores in the last couple of years has been nothing short of phenomenal. It is a complete ecosystem with App Store Developers, App Stores, and the Content Developers and Service Providers. Apps and App stores have changed the rules of the game so completely. No longer is a mobile phone’s snazzy looks enough for it to be a best seller. The mobile should be supported by cool downloadable apps for the user to use. App Stores and apps will play an increasingly important role with apps being developed for smartphones and tablet PCs. There are bound to be several interesting apps spanning technologies like Location Based Service (LBS), mobile Commerce, eTicketing, Near Field Communication

Cloud Computing – Utility computing: Cloud Computing has been around some but is slowly gaining more and more prominence. Cloud computing follows a utility model for computing where the cloud user only pays for the computing power and storage capacity used. Cloud computing not involve any upfront Capacity expenditure (Capex). Users of public clouds like EC2, App Engine or Azure can pay according to the usage of the resources provided by the cloud. Cloud technologies allow the CSPs to purchase processing power, platforms, and databases almost like a utility like electricity or water. The cloud exhibits an elastic behavior and expands to accommodate increasing demands and contracts when the demand drops. Cloud computing will be slowly be adopted by more and more organizations and enterprises in the years to come.

Analytics – Mining intelligence from data: Nowadays organizations all over are faced with a deluge of data. For raw data to be useful it has been analyzed, classified and important patterns determined from the data. This is where data mining and analytics come into play. Analytics uses statistical methods to classify data, determine correlations, identify patterns, and highlight and detect key trends among large data sets. Analytics enables industries to plumb the data sets through the process of selecting, exploring and modeling large amount of data to uncover previously unknown data patterns. The insights which analytics provides can be channelized to business advantage. Data mining and predictive analytics unlock the hidden secrets of data and help businesses make strategic decisions. Analytics is bound to become more common and will play a predominant role in all organizations in the years to come.

Internet TV – Hot off the net: If IMS represents the convergence of Telecom and the internet, Internet TV represents the marriage of TV and the internet. Internet TV is a technology whose time has come. Internet TV will bring a whole new user experience by allowing the viewer to be view rich content on his TV in an interactive manner. The technology titans like Apple, Microsoft and Google have their own version of this technology. Internet TV combines TV, the internet and apps for this new technology. Internet TV is bound to become popular with complementary technologies like IMS, LTE allowing for high speed data exchange and the popularity of websites like Youtube etc. Internet TV will receive a further boost from apps of smartphones and tablet PCs

IPv4 exhaustion – Damocles’ sword: While the future holds the promise of many new technologies it is also going throw a lot of attendant challenges. One serious problem that will need serious attention in the not too distant future is the IPv4 address space exhaustion. This problem may be even more serious than the Y2K problem. The issue is that IPv4 can address only 2 ³² or 4.3 billion devices. Already the pool has been exhausted because of new technologies like IMS which uses an all IP Core and the Internet of things with more devices, sensors connected to the internet – each identified by an IP address. The solution to this problem has been addressed long back and requires that the Internet adopt IPv6 addressing scheme. IPv6 uses 128-bit long address and allows 3.4 x 10³⁸ or 340 trillion, trillion, trillion unique addresses. However the conversion to IPv6 is not happening at the required pace and pretty soon will have to be adopted on war footing. It is clear that while the transition takes place, both IPv4 and IPv6 will co-exist so there will be an additional requirement of devices on the internet to be able to convert from one to another

Conclusion:

Technologies like IMS, LTE, and Internet TV have a lot of potential and hold a lot of promise. We as human beings have a constant need for better, faster and cheaper technologies. We can expect a lot of changes to happen in the next couple of years. We may once see rosy times ahead for telecom as a whole

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