| Abbreviation | Description |
| API | Application Programming Interface |
| CDMA | Code Division Multiple Access |
| CDPD | Cellular Digital Packet Data |
| CSD | Circuit Switched Data |
| EDGE | Enhanced Data for GSM Evolution |
| GPRS | General Packet Radio Service |
| GSM | Global System for Mobile Communications |
| HSCSD | High Speed Circuit Switched Data |
| IAP | Internet Access Point |
| IP | Internet Protocol |
| IPv4 | Internet Protocol version 4 |
| IPv6 | Internet Protocol version 6 |
| LAN | Local Area Network |
| OS | Operating System |
| PDP | Packet Data Protocol |
| PPP | Point-to-Point Protocol |
| UID | Unique Identifier |
| UMTS | Universal Mobile Telecommunication System |
| VPN | Virtual Private Network |
| WCDMA | Wideband Code Division Multiple Access |
| WLAN | Wireless Local Area Network |
| SNAP | Service Network Access Point, actually this is a list of IAPs |
| HSDPA | High Speed Downlink Packet Access |
| Definition | Description |
|---|---|
| Client of connection | An application using a certain connection. Identified with a UID. |
| Connection | In this document, connection refers to an IAP level connection. If two applications have a data connection activated with the same IAP (and therefore the same network interface), the number of connections is 1. Identified with a connection ID. |
| ETel | Symbian OS Telephony Server |
| Sub-connection | A PDP context within a certain IAP. The existing connection has always at least one sub-connection. Currently valid only in case of GPRS/UMTS. If secondary PDP contexts are not used, sub-connection means almost the same as connection. Identified with a sub-connection ID. Support for sub- connections is not implemented. |
| Internal connection | Internal connection has been started by an application running in the phone. |
| External connection | External connection has been started by an application running e.g. in PC and the phone is used in modem mode. |
| IAP availability | IAP is available, if there is an active connection through this IAP, or there is a possibility to start a connection through this IAP, right away |
| SNAP availability | SNAP is available, if there is an available IAP, on which this SNAP is based. |