Ss7 Over Ip

Agilent Technologies and Cisco Systems

SS7 over IP White Paper

SS7 over IP: Out of the Lab and into Operation Telecommunication service providers have been talking about

Agilent and Cisco are pleased to report that these efforts are

the prospects and benefits of moving traffic from SS7

being rewarded: SS7oIP is now a mature, reliable, standards-

signaling networks to SS7-over-IP (SS7oIP) networks for the

based signaling technology that can be monitored and

past few years. What service providers may not realize,

managed as effectively as SS7 traffic in legacy networks. Talk

however, is how far the technology has progressed. Leading

can now become action. Read on to learn the benefits of

technology vendors have been hard at work, not only on their

SS7oIP and the steps technology vendors have taken to move

own products, but also in close collaboration with each other

the technology out of the lab and into commercial operation.

and as active participants in the industry group responsible for developing and standardizing SS7oIP protocols.

Why SS7oIP?

Wireless service providers can remove growing network

SS7oIP can help service providers significantly increase profits,

bottlenecks in a cost-effective manner by using SS7oIP to

even during the current period of economic slowdown. The

increase the bandwidth of links into service nodes such as

technology can be used to improve return on investment in

Short Message Service Centers (SMSCs). IP interface ports on

existing network infrastructure and enable service providers to

service nodes are far more cost-efficient than TDM ports for

offer a wide range of new revenue-generating services.

the equivalent bandwidth, and increased IP-enabled bandwidth reduces TDM facility and infrastructure costs. The transition to SS7oIP will allow wireless service providers to rapidly deploy emerging IP-based services for the mobile Internet that freely interact with the legacy mobile infrastructure. The evolution of the mobile Internet is marked by the same open-spirit characteristic of the wireline Internet, where entrepreneurial vendors compete in the market with unique and compelling applications. Examples include gaming; banking; community chat; directory services; weather, headline and stock-quote services; and direction and map services based on specific location and desired destination.

Initially, service providers can cut costs with SS7oIP by offloading data traffic from SS7 networks onto IP networks. For

These types of applications can generate significant revenues

example, Short Message Service (SMS) data is saturating GSM

for wireless service providers.

service providers' SS7 networks. Using devices such as Cisco IP Transfer Point signaling gateways, service providers can

But Does SS7oIP Work?

stream SMS messaging onto standard IP networks, which

Yes it does. Over the past few years, Agilent, Cisco and other

operate with low cost routers. This solution eliminates the

leading technology vendors have invested the time and

need to upgrade expensive and specialized signaling transfer

resources necessary to ensure that SS7oIP can be reliably and

points (STPs) to handle what amount to very short e-mails, and

effectively deployed. SS7oIP is certainly ready to handle

service providers can improve the flexibility of their legacy SS7

signaling traffic, and developers are already elaborating on the

networks by reducing SMS congestion. SS7oIP provides

basic technology to enable migration to cost-effective all-IP

immediate savings by removing the expense of TDM (time

networks in the near future. SS7oIP has come of age.

division multiplex) leased lines, and it delivers 50 to 75 percent improved transport efficiency. Also, unlike fixed-capacity TDM,

However, in today's uncertain economic environment, service

IP transport requires the use of network capacity only when it

providers will want concrete answers to specific questions

is necessary to transmit data.

before they invest in SS7oIP:

Have SS7oIP protocols been standardized? Will the

telecom professionals who have a track record in SS7 signaling

technology evolve in an open-architecture environment that

that extends far beyond their expertise in IP. The result is a

elicits the innovation and creativity of multiple vendors?

robust session-layer protocol that ensures retransmission and reliable end-to-end delivery of packets in the event of backbone

Have vendors actually demonstrated that their SS7oIP

congestion. The IETF has also standardized in draft form a

solutions can interoperate with solutions from other vendors?

series of adaptation layers on top of STCP that will enable services such as M2PA, M3UA, and SUA (defined in the

Can IP networks deliver the quality of service, fault tolerance

sidebar on page 5). Thus, the industry has been developing

and reliability expected from legacy networks?

standards for nearly two years and has made considerable progress toward bringing the technology to maturity. For details

Is SS7oIP compatible with existing network management

on the IETF Sigtran standards, visit the IETF Web site at

infrastructure? Can SS7oIP be monitored and managed as

www.ietf.org/html.charters/sigtran-charter.html.

effectively as SS7?

Multi-Vendor Interoperability Although the standards and technology continue to evolve, the

Technology vendors can implement industry standards in a

answers to all of these questions are affirmative.

variety of ways, and service providers need to be confident that the products they buy will work together. To this end, the industry has organized a series of technology “bakeoffs" in which multiple vendors come together to test the interoperability of their products. Thus far, up to 18 vendors have attended three events for SCTP. Similar events have been held for M3UA, SUA, and M2PA, and more events are scheduled. In addition to industry-wide bakeoffs, vendors have engaged

SS7 over IP GSM network deployment

in extensive bilateral testing. One important example is the collaborative work between Agilent and Cisco. Agilent has extended its industry-leading acceSS7

Standardization

link monitoring system to cover SS7oIP. Cisco installed the

In early 1999, multiple technology vendors established the

enhanced system in its test lab and conducted a series of tests

Internet Engineering Task Force (IETF) Signaling Transport

to ensure that acceSS7 is compatible with the Cisco IP Transfer

(Sigtran) Working Group, the industry organization responsible

Point (ITP) gateway, which routes SS7 signaling onto IP

for developing and standardizing protocols for the transport of

networks. The companies also successfully tested the

packet-based mobile/PSTN signaling over IP networks. In

interoperability of these products with one of Europe's largest

October 2000, the group officially adopted the Stream

wireless service providers. Similar collaborations and

Transmission Control Protocol (STCP) as the base protocol for

commercial trials are taking place among other vendors

SS7oIP. It is important to note that SCTP was developed by

throughout the industry.

Reliability and Quality of Service

Fortunately, many vendors have adapted their

Before service providers move to SS7oIP, they will need to

management tools to SS7oIP.

know that an IP network's reliability and quality of service (QoS) can match the PSTN's. IP network developers have

Perhaps the most important example of this evolution is

defined procedures to achieve this.

Agilent's successful effort to seamlessly extend acceSS7 to

For example, Cisco's conception of an ITP-enabled network

link monitoring and management system, and it provides

incorporates fault tolerance that ensures infrastructure

network-wide visibility that enables comprehensive network,

reliability through multiple physical connections to the IP

service and revenue assurance. The system includes tools for

backbone. Maximizing the diversity of IP paths provides greater

network surveillance, troubleshooting, business intelligence,

tolerance if a single path become unreachable due to a

fraud detection, interconnect management, roamer

physical link failure. The fully meshed connectivity of an ITP

management, and billing. Service providers use acceSS7 in

network will allow any site to directly route message signaling

their legacy networks to maximize service quality, minimize

units (MSUs) to any other site and reroute around a failed site.

customer churn, enhance revenue generation, and deploy new

ITPs will be deployed in mated pairs, and each device will have

services quickly. Now they can extend the same solution to IP

two Ethernet interfaces to the IP backbone. This architecture

environments.

provides the hardware redundancy required to handle failure in

SS7oIP. Agilent acceSS7 is the world's most widely deployed

an element or interface.

Agilent acceSS7 adds additional value in IP networks when

Technology vendors have developed robust QoS policies to

such as the Cisco Signaling Gateway Manager (SGM). For

enhance the IP backbone's efficiency and reliability and to

example, if a mis-configured ITP routes traffic to the wrong

reduce packet drops and retransmission. The Cisco ITP

destination, acceSS7 will enable operators to locate the device,

gateway, for example, will support IP Precedence and

which they can then reconfigure with Cisco SGM.

deployed in conjunction with element management systems

differential services with eight QoS classes,thus ensuring predictable SS7 service delivery. Enhanced QoS enables service providers to classify various types of SS7 traffic and provide specified classes with preferential treatment over the IP backbone. This capability requires no additional hardware.

Network Management Over the years, service providers have benefited immeasurably from systems that manage signaling networks and network services. These tools provide technical staff with a wealth of knowledge, and service providers have standardized operational practices around them. Indeed, the systems are so valuable that service providers will not likely adopt SS7oIP unless they are confident that the same management capabilities are available in IP networks.

Monitoring of an SS7 over IP Network

Real-World Success

Service providers can be confident that SS7oIP is a mature and

The true test of a technology like SS7oIP comes when service

profitable technology-It is the signaling network technology of

providers assess it in a real network with live traffic. One of

the future, and the future is now.

Europe's leading wireless service providers used the Cisco ITP to carry live SMS traffic between three cities in a trial deployment. Furthermore, this service provider tested the Cisco ITP with Agilent acceSS7 to ensure they can observe signaling traffic across their network when SS7oIP is deployed.

IETF Sigtran Protocols SCTP (Stream Control Transmission Protocol, RFC2960) - transport layer that provides reliable data transfer. M2PA (MTP2-User Peer-to-Peer Adaptation) - provides MTP3 with equivalent transport layer services as MTP2. M3UA (MTP3-User Adaptation) - client/server protocol providing a gateway to legacy SS7 network for IP-based applications that interface at the MTP3 layer. SUA (SCCP-User Adaptation) - client/server protocol providing a gateway to legacy SS7 network for IP-based applications that interface at the SCCP layer.

A call being traced over an SS7 over IP network

The Future Is Now SS7oIP is ready for commercial production. It has been standardized and tested for multi-vendor interoperability; it can be reliably delivered, in accord with comprehensive standards of service quality; and it can be monitored and managed as effectively as legacy SS7 networks. The benefits are significant: reduced infrastructure costs enhanced efficiency new opportunities to deploy revenue-generating applications and services

Agilent Technologies' Support, Services and Assistance By internet, phone, or fax, get assistance with all your communications needs. Online assistance: www.agilent.com/find/assist or for specific Agilent acceSS7 information www.acceSS7.com Phone or Fax United States (tel) 1 800 452 4844 Canada (tel) 1 877 894 4414 (fax) (905) 206 4120 Europe (tel) (31 20) 547 2323 (fax) (31 20) 547 2390 Japan (tel) (81) 426 56 7832 (fax) (81) 426 56 7840 Latin America (tel) (305) 267 4245 (fax) (305) 267 4286 Australia (tel) 1 800 629 485 (fax) (61 3) 9272 0749 New Zealand (tel) 0 800 738 378 (fax) 64 4 495 8950 Asia Pacific (tel) (852) 3197 7777 (fax) (852) 2506 9284 Information in this document subject to change without notice. © Agilent Technologies, Inc. and Cisco Systems, Inc. 2002 Printed in the UK February 1, 2002 Publication number 5988-5730EN

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