If this is a real ISDN circuit to the PSTN, without a carrier on-prem gateway converting the PRI to SIP over Ethernet, it's worth stating that calling name (CNAM) data is not transmitted with the call. Each carrier maintains their own CNAM database that the called party's carrier queries (or maintains a cached copy of) using the calling number (ANI) when they receive the call. Your carrier would need to create CNAM records in their database for your DIDs. This remains accurate with SIP unless the call is VoIP end-to-end. Even then, conveying calling/connected name info may not be passed if the calling and called parties are using different carriers. The classic CNAM database serves as the fallback method.
Also, if the carrier is converting this PRI into SIP immediately after the handoff (common these days), you'd be much better off to use SIP all the way and eliminate the ISDN cross-connect.
Even if this is a real ISDN PRI, I'd convert it from MGCP to SIP between CUCM and the gateway. The SIP Trunk in CUCM has a field to do exactly what you're asking here. It's also a far more modern protocol.
PS- The ASCII Alerting & Display Name fields were intended to be equivelent to their UTF-8 equivalents; they should say the same thing. For example, a user's name in English (ASCII) vs. Japanese (UTF-8). You should not use the ASCII fields for company name; however, if only for trivia purposes: unchecking "Transmit UTF-8 for Calling Party Name" on the MGCP circuit in CUCM should result in the ASCII fields being used; SIP trunks also have this checkbox. CUCM will also use the ASCII fields when the calling/called party Device Pools have different User Locales (e.g. Japanese vs. English).
