G.729 codecs on a SIP Early Offer; it cannot offer both. If CUCM instead does a Delayed Offer and CUBE does the Delayed- Offer-to-Early-Offer interworking, CUBE can offer several codecs in the outgoing SIP INVITE on behalf of CUCM. Codecs might be ordered as desired to suit preferences. Example 10-20 shows a sample configuration for offering different codecs on different calls. Example 10-20 Multiple Codecs on Outgoing Early Offer SIP INVITE voice service voip early-offer forced voice class codec 1 (1) codec preference 1 g729r8 codec preference 2 g711ulaw voice class codec 2 (2) codec preference 1 g711alaw continues 238 SIP Trunking Example 10-20 continued dial-peer voice 100 voip (3) destination-pattern 9011T voice-class codec 2 dial-peer voice 101 voip (4) destination-pattern 91T voice-class codec 1 Note the following: This codec class defines G.729A as the preferred codec and G.711 as a second prefer- ence alternative. This codec class defines G.711 as the only codec to be negotiated. International calls with starting dialed digits of 9-011- trigger both G.729A and G.711 to be sent to the SP as codec choices for negotiation. 4. National calls with starting dialed digits of 91 trigger only G.711 to be sent to the SP as a codec choice for negotiation. SIP Header Manipulation It is often helpful to manipulate SIP messaging when trying to achieve interworking between two systems. The SIP standards are flexible enough that many interoperability difficulties exist even if all equipment is standards-compliant. CUBE offers tools to manip- ulate SIP messages: headers and fields can be added, deleted, or changed (match and replace) using regular expression syntax. These rules can be applied globally to all messag- ing or on a per dial-peer basis for directional traffic. Example 10-21 shows how to remove the timer support indication from an INVITE and instead advertise that the timer feature is not supported. Example 10-21 SIP Header Manipulation voice service voip sip-profiles 100 (1) voice class sip-profiles 100 (2) re