Avaya VF 3000 - Manual (Page 6)

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HT3-LSP-VF.doc
architecture that may occur. This is similar to Figure 1, except that the data center uses public
IP addressing. There is no need for a NAT function between the WAN and the data center in this
case.
2.2. Including LSPs in the Solution
The Juniper VF 3000 SBC proxies the VoIP traffic for the components located at the enterprise
sites and presents all the VoIP traffic to the Avaya Communication Manager with the same IP
address – that of the Juniper VF 3000 SBC inside interface. The Juniper VF 3000 SBC maps all
enterprise IP addresses to this one IP address, and uses different transport layer port numbers to
distinguish between each IP address. The Juniper VF 3000 SBC is not capable of using multiple
inside IP addresses. This means that if all the LSPs in a given enterprise network are presented
to Avaya Communication Manager through the Juniper VF 3000 SBC, the LSPs will all have the
same IP address. However, Avaya Communication Manager is not designed to distinguish LSPs
by port number – but only by unique IP addresses. Therefore, with the current releases of Juniper
VF 3000 SBC and Avaya Communication Manager using the architectures shown in Figures 1-
2, LSP registration must bypass the Juniper VF 3000 SBC.
An Avaya Communication Manager Green feature (“SA8853 – Support of LSPs behind NAT”)
has been developed to allow the registration of LSPs to Avaya Communication Manager in a
way that does not require the ALG function of the Juniper VF 3000 SBC. Figure 3 depicts the
solution architecture when applied to the architecture shown in Figure 1. Note that a separate
NAT/FW device (FW is firewall) has been added to the edge of the data center for LSP-related
traffic only. Also, the NAT function for the LSP in the enterprise site is being handled differently
than for the other components there. A static NAT entry is needed for each LSP.