Link Info

Last updated: July 22, 2008

This section is only applicable to the lab application.

Link Info specifies the parameters ( EMPA Link Parameters , Link Flow Setup , Forward Link Flow Parms , Reverse Link Flow Parms and ROHC Info ) for RLP Flows. When a session is configured, Max Forward Link Flows (Last Negotiated) and Max Reverse Link Flows (Last Negotiated) is negotiated during session negotiation for MaxActivatedRLPFlowsFwd/Rev attributes. Users can define how many Forward and Reverse Link Flows the test set will activate and configure by EMPA Link Parameters . If the value which the user sets is greater than the associated negotiated value when a session is present, the setting will be rejected with the error "Setting Rejected: Number of Link flows cannot be set greater than negotiated number of maximum active RLP flows". There are no restrictions to the user setting value when the session is Idle . After mapping, the Reverse Link Flow will be mapped to the RTC MAC Flow specified by EMPA RTC MAC Flow Mapping . But if the RTC MAC Flow you set is not activated by RTC MAC Flows , the Reverse Link FLow will be mapped to the Default RTC MAC Flow (RTC MAC Flow 01).

EMPA Link Parameters

Number of EMPA Forward Link Flows
This setting sets the number of EMPA Forward Link Flows the test set will configure and activate, including the Default Flow (Flow 00).
Number of EMPA Reverse RLP Flows
This setting sets the number of EMPA Reverse Link Flows the test set will configure and activate, including the Default Flow (Flow 00).

Link Flow Setup

Five Link Flows can be activated and configured for Enhanced Multi-Flow Packet Application. They are Flow 00, Flow 01, Flow 02, Flow 03 and Flow 04. Only when the Flow is activated by the Number of EMPA Forward Link Flows and Number of EMPA Reverse RLP Flows , you can configure this Flow.

Forward Link Flow Parms

EMPA NAK Enable
When this setting is set to Enable, the AT will enable sending NAKs for missing packets on the associated Forward Link Flow NN. When set to Disable, the AT will not send NAKs regardless if the packet is missing.
EMPA Abort Timer (ms)
This setting sets how long the test set will wait before sending the missing octet when it receives the NAK message from the AT. If missing octet has not arrived when its Link abort timer expires, RLP shall pass all octets in the resequencing buffer up to the missing octet, in order of sequence number, to the higher layer. RLP shall skip any missing octets.
EMPA Flush Timer (ms)
After transmitting a packet, the RLP transmitter shall start a Link flush timer. If the RLP transmitter sends another packet before the Link flush timer expires, the RLP transmitter shall reset and restart the timer. If the timer expires, the RLP transmitter shall disable the flush timer and the RLP transmitter should send an RLP packet that contains at least the octet with last sequence number.
EMPA Sequence Length (bits)
The EMPA Sequence Length precedes the Link payload. For MFPA this setting is the result of MFPA Header Size and MFPA RLP ID (Binary) . For EMPA the user can set the sequence length directly, it can be 16, 14 or 22 bits.
EMPA Data Configuration
The testset support five kinds of EMPA Data Configuration:
- HDLC Framing
- Packet/Octet
- Packet/Packet
- ROHC Packet/Packet
- ROHC Packet/Octet
If a Flow's Data Configuration is set to "HDLC Framing" or "Packet/Octet" or "ROHC Packet/Octet" while that Flow's EMPA Link Forward Flow NN Sequence Length / EMPA Link Reverse Flow NN Sequence Length is set to 6, then the setting will be rejected and the error, "Digital856 call processing error; Sequence Length 6 bits not allowed with data configuration set to HDLC framing or octet data unit" will be posted.
EMPA Out of Order Delivery Allowed
This setting sets the FlowNNOutOfOrderDeliveryToRouteProtocolFwd attribute of forward Link Flow NN. If it is set to Off, then each Route of forward Link Flow NN delivers payload to the corresponding instance of the Route Protocol in order.

Reverse Link Flow Parms

EMPA NAK Enable
When this setting is set to Enable, the AN will enable sending NAKs for missing packets on the associated Reverse Link Flow NN. When set to Disable, the AN will not send NAKs regardless if the packet is missing.
EMPA Physical Layer NAK Enable
When this setting is set to Enable, the AN will enable sending NAKs for missing packets on the Reverse Physical Layer. If set to Disable the AN will not send NAKs. If both EMPA NAK Enable and EMPA Physical Layer NAK Enable are enabled in bad channel, the data will be sent up to 3 times: initial sending, resend from physical layer NAK, and resent from RLP layer NAK.
EMPA Transmit Abort Timer Specified State
This setting sets the FlowNNTransmitAbortTimerRev EMPA configuration attribute. When it is set to On, the associated flow's value of FlowNNTransmitAbortTimerRev is set by EMPA Transmit Abort Timer (ms) .
EMPA Transmit Abort Timer (ms)
If EMPA Transmit Abort Timer Specified State is set Specified, then the AT should transmit a higher layer data unit within FlowNNTransmitAbortTimerRev time of the higher layer data unit being received by the Enhanced Multi-flow Packet Application. The AT may use the FlowNNTransmitAbortTimerRev attribute to determine the priority of reverse RLP packets.
EMPA Abort Timer (ms)
This setting sets how long the AT will wait before sending the missing octet when it receives the NAK message from the AN. If missing octet has not arrived when its Link abort timer expires, RLP shall pass all octets in the resequencing buffer up to the missing octet, in order of sequence number, to the higher layer. RLP shall skip any missing octets.
EMPA Flush Timer (ms)
After transmitting a packet, the RLP transmitter shall start an Link flush timer. If the RLP transmitter sends another packet before the RLP flush timer expires, the RLP transmitter shall reset and restart the timer. If the timer expires, the RLP transmitter shall disable the flush timer and the RLP transmitter should send an RLP packet that contains at least the octet with last sequence number.
EMPA Sequence Length (bits)
The EMPA Sequence Length precedes the Link payload. For MFPA this setting is the result of MFPA Header Size and MFPA RLP ID (Binary) . For EMPA the user can set the sequence length directly, it can be 16, 14 or 22 bits.
EMPA Data Configuration
The setting has the same meaning of EMPA Data Configuration described in Forward Link Flow Parms .
EMPA RTC MAC Flow Mapping
This setting determines which EMPA RTC MAC Flow the Reverse Link Flow NN should be transmitted on.
EMPA Data Over Signaling Allowed
When this setting is set to On, the Data Over Signaling (DOS) Protocol for Enhanced Multi-Flow Packet Application is enabled and the EMPA packets can be recepted on the R-Access Channel. The DOS packets sent on the R-Access Channel will be counted in Reverse Link DOS Octets Counter and Reverse Link DOS Packets Counter.

ROHC Info

Link Flow Setup
According to the value of the setting EMPA Link Parameters , the Link Flow Setup setting shows the relative number of the link flow. If one value of the two subsets of EMPA Link Parameters is larger than 2, and the user sets the Link Flow value to no less than 2, ROHC parameters are in-scope (see ROHC Introduction ), as Flow 00 is used to transmit signaling and Flow 01 is inactive in Qualcomm AT, so Flow 02/03/04 are used to transmit IP Packets in ROHC. Then Fwd Link Flow ROHC Parms and Rvs Link Flow ROHC Parms show below this setting.
Fwd Link Flow ROHC Parms
- Max CID
  Context identifier (CID) is an identifier of ROHC context, which is associated with each compressed flow. ROHC context is the state maintained by the compressor and the decompressor in order to correctly compress or decompress the headers of the packet stream. Refer to RFC3095 for more information about ROHC context. Max CID is the highest context ID number to be used by the compressor. The sender shall not set this field to a value greater than Max Supported Max CID .
- Large CID State
  Sets the configurable attribute to limit the range of Max CID. If set to Off, the short CID representation (0 bytes or 1 prefix byte, covering CID 0 to 15) is used; if set to On, the embedded CID representation (1 or 2 embedded CID bytes covering CID 0 to 16383) is used. The sender shall not set this field to On if Large CID Supported is not set to On.
- Maximum Reconstructed Reception Unit(MRRU)
  MRRU is the Maximum reconstructed reception unit. This is the size of the largest reconstructed unit in octets that the decompressor is expected to reassemble from segments. Note that this size includes the CRC. If MRRU is negotiated to be 0, no segment headers are allowed on the link flow. The sender shall not set this field to a value larger than Max Supported MRRU .
- Profile Count
  The profile count is the number of ROHC profiles supported by the decompressor. It determines how many ROHC profiles will be included in FlowNNRouteProtocolParametersFwd/Rev attribute.
- Profile X
  The ROHC profile is a specification of how to compress the headers of a certain kind of packet stream over a link flow. The sender shall not set this field to a value that is not included in the list of Supported Profile .
  
  The test set supports four kinds of ROHC Profile:
  - ROHC Uncompressed (Profile 0): compresses packets, which cannot be compressed by any of the following profiles.
  - ROHC RTP (Profile 1): compresses packets with IP/UDP/RTP protocol headers.
  - ROHC UDP (Profile 2): compresses packets with IP/UDP protocol headers.
  - ROHC ESP (Profile 3): compresses packets with IP/ESP protocol headers.
Rvs Link Flow ROHC Parms
- ROHC Mode
  The setting sets the reverse ROHC mode of operation, which controls the logic of ROHC state transitions and what actions to perform in each state. The ROHC scheme has three modes of operation, called Unidirectional (U-mode), Bidirectional Optimistic (O-mode), and Bidirectional Reliable mode (R-mode).
  
  The value of EMPA Link Reverse Flow NN ROHC Mode setting may not equal to the ROHC Mode in use for a specific EMPA link flow. For example, if EMPA Link Reverse Flow NN Data Configuration for a specific reverse link flow is configured as ROHC, and the Reverse ROHC Mode is O-Mode, but if EMPA Link Forward Flow NN Data Configuration for the corresponding forward link flow is not configured as ROHC, i.e. data configuration (ROHC) for a pair of forward/reverse link flows are not configured symmetrically, in this case, the Reverse ROHC Mode in use will be U-Mode, though the setting is O-Mode.
- Max CID
  The setting has the same meaning of Max CID described in Forward Link Flow Parms .
- Large CID State
  
  The setting has the same meaning of Large CID State described in Forward Link Flow Parms .
- Maximum Reconstructed Reception Unit (MRRU)
  The setting has the same meaning of Maximum Reconstructed Reception Unit(MRRU) described in Forward Link Flow Parms .
- Timer Based Compression State
  This setting indicates if the ROHC compressor supports timer based compression mode. The state only has effect in the Profile type of RTP. The sender shall set this field to Off if Timer Based Comp Supported is not enabled for this ROHC channel. The sender shall set this field to On if Timer Based Comp Supported is enabled for this ROHC channel. If TimerBasedCompressionSupported is set to Off, then the sender shall not set this field to On.
- Profile Count
  The setting has the same meaning of Profile Count described in Forward Link Flow Parms .
- Profile X
  The setting has the same meaning of Profile X described in Forward Link Flow Parms .

NOTE

ROHC Parameters described above once set through the left keys in the testset is shown in the blue pane of the ROHC Info interface. Other relative parameters reported from AT reflecting its the actual abilities described below can be seen in the red pane of the ROHC Info interface.

AT Reported ROHC Capability Information

All ROHC capabilities will be updated whenever a new ATSupportedFlowProtocolParametersPPattribute is received from AT. The values will not be cleared unless full-preset.

Max Supported Max CID
This setting result is the MaxSupportedMaxCID field that AT reported in ATSupportedFlowProtocolParametersPP attribute. This result indicates the maximum MAX_CID parameter supported by the AT.
Large CID Supported
This setting result is the LargeCIDSupported field that AT reported in ATSupportedFlowProtocolParametersPP attribute. This result indicates if the large CID representation is supported by the AT.
Max Supported MRRU
This setting result is the MaxSupportedMRRU field that AT reported in ATSupportedFlowProtocolParametersPP attribute. This result indicates the size (including CRC) of the largest reconstructed unit in octets that the decompressor is expected to reassemble from segments.
Timer Based Comp Supported
This setting result is the TimerBasedCompressionSupported field that AT reported inATSupportedFlowProtocolParametersPP attribute. This result indicates if the ROHC compressor at the AT supports timer based compression mode.
Supported Profile Count
This setting result is the SupportedProfileCount field that AT reported in ATSupportedFlowProtocolParametersPP attribute. This result indicates how many ROHC profiles are supported by the AT.
Supported Profile
This setting result is the SupportedProfile field that AT reported in ATSupportedFlowProtocolParametersPP attribute. This result indicates what ROHC profiles are supported by the AT.

The Testset will translate the bit field to a string. For example, the result may be "0" or "0, 1",or "0, 1, 2".

In ATSupportedFlowProtocolParametersPP attribute, the typical value of SupportedProfileCountis 4, and the SupportedProfile is "0,1,2,3", which means ROHC uncompressed, ROHC RTP,ROHC UDP, ROHC ESP.

NOTE

These settings are accessible only Physical Layer Subtype is


Subtype 2

(see Release A Physical Layer Subtype or Release B Physical Layer Subtype ) and Session Application Type is


Enh M-Flow Pkt

All ROHC Parameters per Link Flow are only in-scope when EMPA Link Forward Flow NN Data Configuration / EMPA Link Reverse Flow NN Data Configuration is set to "ROHC with Packet PDU and Packet Data Unit" and "ROHC with Packet PDU and Octet Data Unit". All the settings described above except ROHC Mode once set, will be re-negotiated via GCP if in-scope.