Table 13-1

Standards Supported

Standard		Transmission rate1	Notes
G.711	ITU standard for voice codecs	64 Kbps	ISDN voice quality
G.722	High-quality voice codec	48, 56 or 64 Kbps	Better voice quality than G.711
G.723.1	ITU standard for voice codecs	5.3 or 6.3 Kbps	Adequate voice quality
G.729	Group of ITU standards for voice codecs	8 Kbps	Less delay and better voice quality than G.723.1
G.729A	ITU standard for voice codecs, based on G.729	8 Kbps	Less delay and better voice quality than G.723.1
G.729AB	ITU standard for voice codecs, based on G.729A	8 Kbps	Less delay and better voice quality than G.723.1
T.38	ITU standard for fax transmission (Realtime FAX)	14 Kbps	Governs communication from group 3 fax devices over IP networks

1The bandwidth actually required in the LAN, for example, may be considerably higher. Here are some relevant factors: - Data Link Layer used: Ethernet (with or without VLAN), PPP, Frame Relay ... - Protocols with/without compression: RTP, UDP, IP - Security: VPN tunnel ... - Redundancy: For example T.38 - Packaging: the number of samples that are transported per package.