Traffic shaping

The traffic shaping function estimates the parameters of the incoming traffic. If the incoming traffic exceeds the defined parameters, Branch Gateway can drop the packets or mark them as low-priority.

PPP over channeled and fractional E1/T1

Branch Gateway can map several PPP sessions to a single E1/T1 interface.

PPP over Universal Serial Port

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PPPoE

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Unframed E1

Enables full 2.048 Mbps bandwidth usage.

Point-to-Point Frame Relay encapsulation

Supported over channelized, fractional, or unframed E1/T1 ports or over a Universal Serial Port interface.

Frame Relay LMI

The following Frame Relay LMI types are supported:

• ANSI (Annex D)

• ITU-T:Q-933 (Annex A0)

• LMI-Rev1

• No LMI

Backup functionality

Supported between any type of Serial Layer 2 interface.

Dynamic Call Admission Control (CAC) for Fast Ethernet, Serial, and GRE tunnel interfaces

Dynamic CAC provides enhanced control over the WAN bandwidth. When Dynamic CAC is enabled on an interface, Branch Gateway tells the MGC to block calls when the interface bandwidth is exhausted.

Quality of Service (QoS)

Branch Gateway uses Weighted Fair VoIP Queuing (WFVQ) as the default queuing mode for WAN interfaces. WFVQ combines weighted fair queuing (WFQ) for data streams and priority VoIP queuing to provide real-time responses required for VoIP. Branch Gateway also supports the VoIP Queue and Priority Queue legacy queuing methods.

Weighted Random Early Detection (WRED)

Branch Gateway uses WRED on its ingress and egress queues to improve the network performance. WRED reduces host transmission speed when the ingress Branch Gateway queues are congested.

Policy

Each interface on Branch Gateway can have four active policy lists:

• Ingress Access Control List

• Ingress QoS List

• Egress Access Control List

• Egress QoS List

Access control lists defines which packets to forward or block. QoS lists change the DSCP and 802.1p priority of routed packets according to packet characteristics.

Policy-based routing

Branch Gateway features policy-based routing, which uses a policy-list structure to implement a routing scheme based on traffic source, destination, type, and other characteristics. You can use policy-based routing lists (PBR lists) to determine routing of packets that match the rules defined in the list. Common applications include separate routing for voice and data traffic, routing traffic originating from different sets of users through different Internet connections, and defining backup routes for classes of traffic.

RTP Header Compression

Branch Gateway saves the bandwidth using RTP compression. It also enhances the efficiency of voice transmission over the network by compressing the headers of RTP packets, minimizing overhead and delays involved in the RTP implementation.

TCP Header Compression

Branch Gateway uses TCP header compression to reduce the amount of bandwidth needed for non-voice data. TCP header compression can be applied either as a part of RTP Header Compression through IPCH, or using the Van Jacobson method defined in RFC 1144.

Inter-Gateway Alternate Routing (IGAR)

Branch Gateway uses PSTN as an alternative to the WAN interface under certain definable conditions. In providing an alternate routing mechanism, IGAR preserves the call internal makeup so that it can be successfully terminated to its original internal destination.