SIP is the signaling protocol standard for next-generation 3GPP mobile wireless networks. Acme Packet Net-Net delivers peak performance for wireless networks providing IP-based interactive communication services to mobile subscribers. With Acme Packet, wireless network operators can satisfy critical network security, SLA assurance, revenue and profit assurance, and law enforcement requirements in four areas:

	1.		Connecting access networks to the IP Multimedia Subsystem network
	2.		Load balancing SIP application servers
	3.		Routing and load balancing for PSTN breakout gateways
	4.		Connecting other service provider IP networks for termination or transit

Net-Net benefits & features

	•		Access control - session-based pinhole firewall
	•		Network topology hiding for SIP (layers 3 & 5)
	•		Signaling message rate limiting

SLA assurance
	•		Session admission control - available access link bandwidth
	•		L2 & L3 QoS marking - IEEE 802.1p & q (VLAN), ToS, DiffServ, MPLS
	•		Application server & gateway load balancing
	•		Real-time QoS-based routing - IP transit and PSTN termination networks
	•		QoS reporting - SLA reporting, problem isolation, routing

Revenue & profit assurance
	•		Real-time cost-based routing - internal gateways, PSTN termination and IP transit networks
	•		Dynamic routing policy exchange
	•		Bandwidth policing
	•		Accounting with session timers

Law enforcement
	•		Session replication and routing for lawful intercept (e.g. CALEA)

Connecting the IP Multimedia Subsystem network

Acme Packet Net-Net performs 3G's Proxy and Interrogating Call Session Control Functions (CSCF) for controlling session establishment across visited and home networks in separate service provider network domains, and complements GPRS Support Nodes (GSN) for media control. In these roles, Acme Packet Net-Net satisfies critical security, SLA assurance, revenue and profit assurance and law enforcement requirements. Acme Packet Net-Net also performs 3G's Serving-CSCF for routing sessions to SIP application servers located in IP networks outside the 3G multimedia network.

Security - To protect internal network resources, such as SIP servers, gateways, and application servers, from DoS attack, Net-Net explicitly authorizes incoming sessions and hides internal network topology information in both signaling messages and media flows. To protect against infrastructure overloads, incoming signaling messages can be intelligently throttled.

SLA assurance - Acme Packet Net-Net performs session admission control based upon the available bandwidth in the on the link to the access network. If no bandwidth is available, the call will be rejected because acceptance would deteriorate the quality of all active calls. Net-Net further assures SLA performance and optimal traffic management within the service provider's network by explicitly assigning required QoS markings at both Layer 2 and 3 for signaling messages and media flows. Reporting capabilities include per-session, end-to-end QoS measurements for SLA reporting, problem alerting and problem isolation. The source of poor quality can be isolated by network domain and by path within any network using Acme Packet equipment.

Revenue and profit assurance - A bandwidth policing feature protects revenue and profits by preventing a low bandwidth voice call from turning into a high bandwidth multimedia session without explicit authorization. Comprehensive per session accounting records are produced for tracking or billing purposes.

Law enforcement - Acme Packet Net-Net satisfies law enforcement requirements for legal intercept, such as CALEA, by supporting transparent session replication and routing of signaling messages and media flows to law enforcement agencies.

Load balancing SIP application servers

SIP application servers are used to deliver unified messaging, presence and instant messaging, location-based information, conferencing, and other applications. Multiple servers are required to provide redundancy and capacity for each application. Acme Packet Net-Net assures SLA performance by distributing requests to the least-loaded available server, protecting against failure and overload.

Routing and load balancing for PSTN breakout gateways

The Breakout Gateway Control Function (BGCF) in 3G networks handles routing of SIP-signaled sessions to breakout gateways connecting the PSTN. Multiple distributed gateways are required for geographic coverage, redundancy, and capacity. Acme Packet Net-Net routes each session to the correct gateway to minimize PSTN termination charges and assures SLA performance by distributing calls to the least-loaded available gateway, protecting against failure and overload.

Connecting other service provider IP networks for termination or transit

To extend the reach and value of their IP networks for interactive communications, such as presence-based instant calling and conferencing between mobile subscribers and non-mobile users, service providers will need to establish business and network relationships with other service providers for IP-based session transit and termination, and PSTN origination and termination.

Acme Packet Net-Net performs critical security, SLA assurance, and revenue and profit assurance functions required for connecting these IP networks.

Security - To protect internal network resources, such as SIP proxies, softswitches, gateways, and application servers, from DoS attack, Acme Packet Net-Net explicitly authorizes incoming sessions and hides internal network topology information in both signaling messages and media flows. To protect against infrastructure overloads, incoming-signaling messages can be intelligently throttled.

SLA assurance - Acme Packet Net-Net supports session admission control based upon the available bandwidth on the transit link between service provider networks. If no bandwidth is available, the call will be gracefully rejected because acceptance would deteriorate the quality of all active calls. Net-Net also supports admission control into a transit or termination IP network based upon observed QoS. If observed QoS is unacceptable, calls requiring that network will be rejected. If there is more than one path to a destination, Net-Net can also perform optimal SIP routing based upon the session's QoS requirements. Net-Net further assures SLA performance and optimal traffic management within the service provider's backbone by explicitly assigning required QoS markings to incoming traffic at both Layer 2 and 3 for signaling messages and media flows. Reporting capabilities include per-session, end-to-end QoS measurements for SLA reporting, problem alerting, problem isolation and routing. The source of poor quality can be isolated to the source/destination transit or termination network(s) or the service provider's backbone.

Revenue and profit assurance - Acme Packet Net-Net enables policy-based SIP routing and admission control to other IP networks based upon cost, time, service provider preference, and source/destination URI/telephone number. The dynamic, automatic exchange of session routing information within and between networks using TRIP eliminates all configuration and synchronization burdens. With Net-Net's SIP-H.323 interworking a provider can build a single SIP backbone and leverage SIP or H.323 transit or termination networks to maximize network reach. A bandwidth-policing feature protects revenue and profits by preventing a low bandwidth voice call initiated within another network from turning into a high bandwidth video call without explicit authorization. Net-Net's QoS marking feature also protects against QoS theft by eliminating the requirement to trust any markings on packets coming from another network. Comprehensive per session accounting records are produced for tracking or billing purposes.