Capacity

In dual-stack deployments, because calls between IPv4 and IPv6 devices are through forced gateway, an extra load in the media gateway resources is compared to a deployment that uses only either IPv4 or IPv6.

As an example, when there is a call from IPv6 SIP phone to an IPv4 SIP phone, the SIP signaling goes through MX-ONE Service Node and the Media goes through Media Server as a gateway call. The Media Server transcodes the IPv6-IPv4 address without any manipulation in the media packets. The capacity load in such a case is lower than that in a normal gateway call.

In scenario depicted in the following figure, a customer has SIP phones running both IPv6 and IPv4 addresses.

The same IPv4-IPv6 scenario described in Figure 4 applies when TLS is used to encrypt SIP signaling and SRTP is used to encrypt the Media.

The codec transcoding is executed in the same way as in an IPv4 implementation.

The following table shows how the different types of extensions are interconnected through media gateways.