ress that will be sending the media packets, which could be either multicast or unicast. If multicast, the connection-address field contains: Related Protocols connection-address=base-multicast-address/ttl/number-of- addresses where ttl is the time-to-live value, and number-of-addresses indicates how many contiguous multicast addresses are included starting with the base-multicast-address 7.1.7 Bandwidth The optional b= field contains information about the bandwidth required. It is of the form: b=modifier:bandwidth-value The modifier is either CT for conference total or AS for application specific. CT is used for multicast session to specify the total bandwidth that can be used by all participants in the session. AS is used to specify the bandwidth of a single site. The bandwidth-value parameter is the specified number of kilobytes per second. 7.1.8 Time, Repeat Times, and Time Zones The t = field contains the start time and stop time of the session. t=start-time stop-time The times are specified using NTP timestamps. For a scheduled session, a stop-time of zero indicates that the session goes on indefinitely. A start-time - and stop-time of zero for a scheduled session indicates that it is permanent. The optional r= field contains information about the repeat times that can be specified in either in NTP or in days (d), hours (h), or minutes (m). The optional Z = field contains information about the time zone offsets. This field is used if a reoccurring session spans a change from daylight-savings to standard time, or vice versa. 7.1.9 Encryption Keys The optional k= field contains the encryption key to be used for the media ses- sion. The field contains: k=method encryption-key The method parameter can be clear, base64, uri, or prompt. If the method is prompt, the key will not be carried in SDP; instead, the user will be SIP: Understanding the Session Initiation Protocol prompted as they join the encrypted session. Otherwise, the key is sent in the encryption-key parameter. 7.1.10 Media Announcements The optiona