VoIP Peering and Interconnect

Market and Requirement

VoIP Peering and Interconnect have grown to be used somewhat interchangeably recently. In general VoIP Peering refers to the connection of two operators to exchange traffic and VoIP Interconnect refers to formalised national standards that must be met when interconnecting with a national operator. However, the requirements when exchanging traffic in either case are generally the same. The terms are used interchangeably in the following description (exceptions are highlighted).

To illustrate the speed with which networks are moving to VoIP Peering and Interconnect, iLocus estimate that in the year to June 2005, 25% to 30% of all international long distance traffic was carried over IP. Several countries have also now announced plans to start migration to national IP interconnect starting in 2005 and 2006.

In a Peering and Interconnect environment session border controllers form the border between network operators. Here they secure the network border, enforce Quality of Service policies, ensure any intermediate NAT and firewalls can be traversed, and provide regulatory compliance.

Critically, at the Peering and Interconnect point, there is an expectation of high service availability with consistent Quality of Service levels. This requirement flows through into equipment design where resilience and redundancy must be part of product design from day one; as is the case with the Newport Networks 1460. A network diagram is shown below:

The following will be key when deploying session border control solutions if a carrier's investment return is to be maximised when used in a peering and interconnect environment:

Session border controllers must be able to scale flexibly and to a large capacity to deal with the volumes of traffic between operators.
They must allow the use of overlapping IP address spaces.
They must provide security for the operators core network, whilst also preventing service theft.
They must be capable of being deployed in a flexible manner. Signalling and media resource must be physically separable to meet the deployment scenarios of some operators and national specifications of some countries.
They must provide regulatory service such Lawful Intercept.
They must be capable of evolving to IMS and TISPAN architectures to ensure investment reuse as the carrier's network moves towards the converged network architecture space.

The Newport Networks 1460 is the only product that is capable of providing the required level of feature function today, and also provides the level of flexibility required to deal with a rapidly expanding user base and uncertain network evolution requirements.

Key Newport Networks 1460 VoIP Peering and Interconnect Capabilities

Future Proof Investment

The 1460 can be deployed as a traditional session border controller or it can be physically separated into a MediaProxy and SignallingProxy providing deployment flexibility. This configuration is particularly applicable to peering / interconnect configurations where most deployments centralise signalling control and distribute media control.
Multiple MediaProxies can be controlled from one SignallingProxy if required.
Common hardware is used in combined session border control deployments and separated signalling and media deployments.

Both combined session border control deployments and separated signalling and media deployments can be upgraded for IMS and converged network use as required by the network operator ensuring maximum investment reuse.

Resilience

The 1460 has no single point of failure providing in excess of 99.999% availability.
All system modules are 1 + 1 resilient including power distribution units, fans and disks.
Physical link aggregation (802.3-2002) provides link resilience and load balancing.

Access Reach

Secure traversal of NAT and firewall devices if deployed in the core network between operators.
VLAN support allows connection to multiple peering partners with overlapping address spaces. Also allows grooming of multiple peering partners onto one physical interface or Link Aggregation Group thus saving hardware costs.
Scaling from 5,000 to 100,000 simultaneous bi-directional calls on a single chassis.

Quality of Service

Session Admission Control applied to each peering/interconnect partner. Admission based on total bandwidth currently used and session count (by media type and codec type)
Bandwidth Policing to ensure sessions do not exceed total negotiated peering/interconnect rate for that partner.
Type of Service (ToS) and DiffServe Code Point (DSCP) remapping / interworking to ensure adherence to Quality of Service plan in each network
Load balancing across multiple core network Softswitches/Proxies.

Security

Network Address and Port Translation (NAPT) provides topology hiding for core network from peering and interconnect partners.
Malformed or 'illegal' SIP signalling discarded.
Policing of signalling traffic (rate limiting), media traffic and quality monitoring (RTCP) stream. This prevents inappropriate use (fraud).

Regulatory

Lawful Intercept for CALEA and ETSI.
Supported national variants including, but not limited to: USA, Canada, UK, Germany, Italy.
Emergency Call Handling facilities allowing Session Admission Control to be suspended for emergency calls and calls to be passed to designated Emergency Call Handling Proxies