3 Asterisk currently supports configurable RTP packetization per codec for
4 select RTP-based channels.
8 These channel drivers allow RTP packetization on a user/peer/friend
13 chan_ooh323 (Asterisk-Addons)
17 To set a desired packetization interval on a specific codec,
18 append that inteval to the allow= statement.
21 allow=ulaw:30,alaw,g729:60
23 No packetization is specified in the case of alaw in this example,
24 so the default of 20ms is used.
28 In addition, chan_sip has the ability to negotiate the desired
29 framing at call establishment.
31 In sip.conf if autoframing=yes is set in the global section, then
32 all calls will try to set the packetization based on the remote
33 endpoint's preferences. This behaviour depends on the endpoints
34 ability to present the desired packetization (ptime:) in the SDP.
35 If the endpoint does not include a ptime attribute, the call will
36 be established with 20ms packetization.
38 Autoframing can be set at the global level or on a user/peer/friend
39 basis. If it is enabled at the global level, it applies to all
40 users/peers/friends regardless of their prefered codec packetization.
44 The following table lists the minimum and maximum values that are
45 valid per codec, as well as the increment value used for each.
46 Please note that the maximum values here are only recommended
47 maximums, and should not exceed the RTP MTU.
49 Name Min Max Default Increment
61 g726_aal2 10 300 20 10
63 Invalid framing options are handled based on the following rules:
64 1. If the specified framing is less than the codec's minimum, then
65 the minimum value is used.
66 2. If the specific framing is greater than the codec's maximum, then
67 the maximum value is used
68 3. If the specificed framing does not meet the increment requirement,
69 the specified framing is rounded down to the closest valid
71 example allow=ulaw:33 will set the codec to 30ms framing
72 4. If no framing is specified in the allow= directive, then the
73 codec default is used.