Comparison at a Glance
| H.323 | SIP | H.248(Megaco)/MGCP | |
|---|---|---|---|
| Hype | None | High | None |
| Philosophy | Unified | Modular | Unified |
| Complexity | High | High | Moderate |
| Scope | Full | Limited | Partial |
| Scalability | Good | Good | N.A. (it's a tool for scalability) |
| PSTN Interworking | Yes | Somewhat | Yes |
| SS7 Compatibility | Good | Poor | Good |
| Cost | Moderate | Moderate | Moderate |
| Message Size | Small | Large | Moderate |
| Router Fragmentation | Unlikely | Likely | Unlikely |
| Volatility of Standard | Low | High | Low |
| Multimedia | Good | Poor | Poor |
| Usage-Billing Fit | Good | Poor | N.A. |
| Monthly Billable Call Minutes | 1,000,000,000's | 10,000s | 100,000s |