2.13.6.4 Interaction between SLS Conversion Algorithms

This section describes the interaction of SLS conversion algorithms during network conversion:

• ITU to ANSI Conversion

  The following table describes the interaction between different SLS conversion algorithms and the associated outgoing SLSs for ITU to ANSI Conversions:

  Table 2-19 Interaction between SLS Conversion Algorithms - (ITU to ANSI Conversion)

  randsls	5-bit to 8-bit conversion	islsbr	slsreplace	Bits for Linkset /Link Selection	Outgoing SLS
  No	No	No	Has no impact	5 bits obtained after 4-bit ITU to 5-bit ANSI Conversion	5 bits obtained after 4-bit ITU to 5-bit ANSI Conversion
  No	No	Yes	Has no impact	Rotated 5 bits	5 bits obtained after 4-bit ITU to 5-bit ANSI Conversion
  No	Yes	No	Has no impact	Converted 8 bits	Converted 8 bits
  No	Yes	Yes	Has no impact	Converted and rotated 8 bits	Converted 8 bits
  Yes	No	No	No	Random 8 bits	5 bits obtained after 4-bit ITU to 5-bit ANSI Conversion
  Yes	No	No	Yes	Random 8 bits	Random 8 bits
  Yes	No	Yes	Has no impact	NA	NA
  Yes	Yes	No	No	Converted 8 bits	Converted 8 bits
  Yes	Yes	No	Yes	NA	NA
  Yes	Yes	Yes	Has no impact	NA	NA

  As per the above table, the following are the key points during ITU to ANSI conversion:

  • The randsls and islsbr parameters are mutually exclusive.

  • The randsls and 5-bit to 8-bit SLS conversion are mutually exclusive when slsreplace flag is ON.

  • The slsbr parameter is not applicable for ITU to ANSI network conversions because in case of these conversions, messages are already converted to ANSI by the time slsbr is applied. Also, slsbr is applicable only for ITU MSUs.

  • During ITU to ANSI network conversion, the ingress linkset is ITU, hence the value of asls8 will always be No. Therefore, if randsls is applied after ITU to ANSI network conversion, the outgoing SLS will be of 5 or 8 bits, depending on the values of the m3rloptions,slsreplace and LINKSET(EGRESS), slsci /m3rloptions, or slscnv parameters.

• ANSI to ITU Conversion

The following table describes the interaction between different SLS conversion algorithms and the associated outgoing SLSs for ANSI to ITU Conversions:

Table 2-20 Interaction between SLS Conversion Algorithms - (ANSI to ITU Conversion)

randsls	4-bit to 8-bit conversion	islsbr/slsbr	Bits for Linkset /Link Selection	Outgoing SLS
No	No	No	4 bits obtained after 5-bit to 4-bit or 8-bit to 4bit ANSI-ITU SLS Conversion	4 bits obtained after 5-bit to 4-bit or 8-bit to 4bit ANSI-ITU SLS Conversion
No	No	Yes	Rotated 4 bits	4 bits obtained after 5-bit to 4-bit or 8-bit to 4bit ANSI-ITU SLS Conversion
No	Yes	No	Converted 8 bits	4 bits obtained after 5-bit to 4-bit or 8-bit to 4bit ANSI-ITU SLS Conversion
No	Yes	Yes	Converted and rotated 8 bits	4 bits obtained after 5-bit to 4-bit or 8-bit to 4bit ANSI-ITU SLS Conversion
Yes	No	No	Random 8 bits	4 bits obtained after 5-bit to 4-bit or 8-bit to 4bit ANSI-ITU SLS Conversion
Yes	No	Yes	NA	NA
Yes	Yes	No	NA	NA
Yes	Yes	Yes	NA	NA

As per the above table, the following are the key points during ANSI to ITU conversion:

• The randsls and islsbr/slsbr parameters are mutually exclusive.

• The randsls and 4-bit to 8-bit SLS conversion are mutually exclusive.