This object specifies the payload size (in bytes) of
packets transmitted to the Packet Service Network (PSN)
by the CEM SAP.  This determines the size of the data
that will be transmitted over the service.  As well,
if the size of the data received is not consistent with
the payload size then the packet is considered malformed.

Default value depends on the CEM SAP endpoint type
(sapCemEndpointType), and if applicable, the number of
timeslots (sapCemBitrate):
---------------------------------------------------------
| Endpoint Type      | Timeslots | Default payload size |
---------------------+-----------+-----------------------
| 'unstructuredE1'   | n/a       |    256 bytes         |
---------------------+-----------+-----------------------
| 'unstructuredT1'   | n/a       |    192 bytes         |
---------------------+-----------+-----------------------
| 'unstructuredE3'   | n/a       |   1024 bytes         |
---------------------+-----------+-----------------------
| 'unstructuredT3'   | n/a       |   1024 bytes         |
---------------------+-----------+-----------------------
| 'nxDS0' (E1/T1)    | N = 1     |     64 bytes         |
|                    +-----------+-----------------------
|                    | N = 2..4  | N x 32 bytes         |
|                    +-----------+-----------------------
|                    | N = 5..15 | N x 16 bytes         |
|                    +-----------+-----------------------
|                    | N >= 16   | N x  8 bytes         |
---------------------+-----------+-----------------------
| 'nxDS0WithCas' (E1)| N         | N x 16 bytes         |
---------------------+-----------+-----------------------
| 'nxDS0WithCas' (T1)| N         | N x 24 bytes         |
---------------------------------------------------------

For all endpoint types except for 'nxDS0WithCas',
valid payload size range is from the default (in the
table above) to 2048 bytes.  

For 'nxDS0WithCas', sapCemPayloadSize divide by the
number of timeslots (sapCemBitrate) must be an integer
factor of the number of frames per trunk multiframe (i.e.
16 for E1 trunk and 24 for T1 trunk).

For '1xDS0', sapCemPayloadSize must be a multiple of 2.

For 'NxDS0', where N > 1, sapCemPayloadSize must be a
multiple of the number of timeslots (sapCemBitrate).

For 'unstructuredE1', 'unstructuredT1', 'unstructuredE3'
and 'unstructuredT3', sapCemPayloadSize must be a
multiple of 32 bytes.

Configuring sapCemPayloadSize and sapCemJitterBuffer to
values that result in less than 2 packet buffers or
greater than 32 packet buffer is not allowed.

Setting this object to 0 sets it back to the default
value.