C.4 S-NAPTR procedure pseudo-code with topon

29.3033GPPDomain Name System ProceduresRelease 17Stage 3TS

Collocation, when stated as specifically applicable in a procedure, takes precedence over other criteria such as topological ordering or S-NAPTR ordering. Topological ordering, when stated as specifically applicable in a procedure, takes precedence over S-NAPTR ordering. However, S-NAPTR ordering is used for ordering nodes with equivalent topological distances. Pseudo code below is informative and shows how to implement the ordering of record selection. See clause 4.3.2 for normative text.

Assume two distinct types of nodes "A" and "B" are being checked for closeness and the best record pair is needed. First step, which is documented in each case in the main text of this document is to get two candidate lists using a procedure such as that outlined in clause C.3.

candidate_list_A:= get_candidates (targetFQDN_A,desired_service_and_protocol_set_A, "A");

candidate_list_B:= get_candidates (targetFQDN_B,desired_service_and_protocol_set_B, "B");

As an example take the selection of a PGW and SGW by an MME during a UE initial attach procedure. Both a PGW and SGW need to be selected and if "topon" is used in both lists the selected pair is to be as close as possible (collocated being the closest).

Sometimes one list in the procedure is not found by DNS (or was found previously) because the node was already selected. In that case, one of the candidate lists can be just one node.

For example, an UE with an existing PDN connection adds a new PDN connection to a different APN, which may result in a different PGW but needs to continue using the current SGW. Here one of the two candidate lists would just be the data for the current SGW node (i.e., its node name and whether it supports GTPv2 and/or PMIPv6 for S5/S8).

The following pseudo-code illustrates topological matching with full ordering.

procedure topo_matching (candidate_list_A,candidate_list_B, topology_check, colocation_check)// Comment: topology_check and colocation_check are booleans indicating if those checks are done

Begin procedure

paired_sets_list:=empty;

if (colocation_check)

Begin if

total_list:= candidate_list_A appended with candidate_list B;

// Comment: Below canonical_node_name is the hostname with first two labels removed

Foreach unique canonical_node_name from total_list do

Begin foreach

Foreach servce and protocol do

Begin foreach

full_match_list:= get all records from total_list with service and protocol

and canonical_node name

If there is at least one "A" record and one "B" record in full_match_list then

Begin If

degree:=256;

suffix:=canonical_node_name;

create structure with fields

(degree, suffix,service_and_protocol,full_match_list)

add that structure to paired_sets_list

End If

End foreach

End foreach

End if;

if (topology_check) Begin if

max_labels:= (maximum number of DNS labels in total_list)- 2

else

max_labels =0;

End If;

from number_labels_to_match:= max_labels down to 0 do

Begin do

if number_labels_to_match equals 0 then

Begin if

total_list:= candidate_list_A appended with candidate_list B

else

total_list:= get all records from candidate_list_A and candidate_list_B
with "topon" as first label and hostname has at least

(number_labels_to_match+2) labels

// Comment: Add 2 since the first two labels are not part of the node name End If;

// Comment: Below suffix is a hostname chopped off to include only the last number_labels_to_match

Foreach unique suffix from total_list do

Begin foreach

Foreach servce and protocol do

Begin foreach

full_match_list:= get all records from total_list with service and protocol

and suffix contained in end of the hostname

If there is at least one "A" record and one "B" record in full_match_list then

Begin If

degree:=number_labels

create structure with fields

(degree, suffix,service_and_protocol,full_match_list)

add that structure to paired_sets_list

End If

End foreach

End foreach

End do

sort paired_sets by degree

return (paired_sets_list)

End Procedure;

NOTE 1: Matching collocated nodes get a degree of 256, which is above any normal match. Also the above procedure is specific to this document and is not a part of S-NAPTR.

NOTE 2: Order from S-NAPTR is from one S-NAPTR procedure. There is no meaningful order obtained from S-NAPTR between records from two different S-NAPTR procedures. So one node type will be selected "logically first" based on other criteria outside S-NAPTR information.

The above procedure simply creates a list of records which are sorted by decreasing degree of matching in DNS labels. It also gives the list of paired nodes with the same suffix and compatible service which is needed by the 3GPP application.

Since highest degree is preferred over S-NAPTR ordering with "topon" labels the selection is done by degree starting with the highest degree obtaining only the possible "A" and "B" nodes at that degree. A sublist of the paired_sets_list containing the highest degree is taken from paired_sets_list denoted as degree_sublist. Assume the "A" node is to be selected "logically first". Sort the "A" parts of degree_sublist in increasing "snaptr_output_order". For the records in that order try to connect to the node with the service and protocol in the record using 3GPP procedures. On failure proceed with the next record. When that degree_sublist is exhausted then degree-1 is tried and so on until an "A" node is selected. Once an "A" node is chosen, the procedure has also a selected degree, suffix and service.

NOTE 3: The remaining part of this procedure is not needed if the "B" node was already pre-selected outside the present procedure.

Taking the degree_sublist used to select the "A" node create a new sublist from only records with the same service, same protocol and suffix. Remove the "A" node records from that sublist. Sort this new sublist by increasing "snaptr_output_order" (see clause C.3). Using the records in that order try to connect to the "B" nodes with the service and protocol in the record. On a failure proceed with the next record. When that list is exhausted the procedure continues in next paragraph.

NOTE 4: The suffix of the "A" node that was selected influences which "B" nodes are closest to it. We can’t easily and simply reuse the above structure for that reason and it is easier to "reset" the procedure.

A new candidate_list_A is created consisting only of the selected "A" node A and service_and_protocol. The procedure "topo_matching " is run again giving a new paired_sets_list. The "A" node records are removed from the new paired_sets_list leaving only "B" nodes. Sort the records in paired_sets_list in decreasing order of degree and within degree in increasing "snaptr_output_order" (see clause C.3). Using the records in that order try to connect to the "B" nodes with the service in the record. On failure go to next record.

NOTE 5: Failing to actually contact a node should result in the failing node(s) to be removed from consideration for a period of time. Such removal is not detailed above. Also a reasonable implementation would give up after some maximum number of failed attempts.

Annex D (Informative):
SGSN examples

D.1 Introduction

This annex includes examples of the DNS provisioning needed for an SGSN discovery and selection procedures. Examples are not exhaustive either in scope or in content but are intended to be sufficient to illustrate the general techniques and some of the more important use cases.

D.2 Preconditions

Provisions of annex A.2 apply also here.

D.3 SGSN file

A NAPTR record is required to be provisioned under the NRI-RAI FQDN (see clause 4.3.3.5 of this TS). The format of the NRI-RAI FQDN is nri-sgsn<NRI>.rac<RAC>.lac<LAC>.rac as defined in clause 19.4.2.6 of 3GPP TS 23.003 [4].

The nri-sgsn<NRI>.rac<RAC>.lac<LAC>.rac is also the natural place for the SGSN canonical node record set. For this example we place the SGSN canonical node records and the required record for the lookup at the same location both for simplicity and better DNS caching.

For this example we have two SGSNs with NRI codes of 1 and 2 respectively and both in the same SGSN pool (LAC = 1000 hexadecimal and RAC = 0003 hexadecimal).

;

; This is the P-TMSI and RAI related record and the SGSN node record

; The operator has decided to use the 3GPP name as the canononical node name of the SGSN

; rather than having two records (the 3GPP one and an operator defined value)

;

nri-sgsn01.rac0003.lac1001.rac

; IN NAPTR order pref. flag service regexp replacement

IN NAPTR 200 999 "a" "x-3gpp-sgsn:x-s4" "" topoff.eth1.nri-sgsn01.rac0003.lac1001.rac

IN NAPTR 200 999 "a" "x-3gpp-sgsn:x-s3" "" topoff.eth2.nri-sgsn01.rac0003.lac1001.rac

IN NAPTR 300 999 "a" "x-3gpp-sgsn:x-gn" "" topoff.eth3.nri-sgsn01.rac0003.lac1001.rac

;

; Reminder: Canonical node name records must be complete.

; In most cases the interface type (S3 etc) is functionally determined so the NAPTR order is rarely

; used in this record set. The S3 is preferred over over Gn.

;

; Of course if the SGSN had multiple S3 interfaces

; the operator could provision more than one S3 record with different orders

; perhaps to select S3 IPv6 over S3 IPv4

; We have the same type of records for the other SGSN (same comments would apply)

;

nri-sgsn02.rac0003.lac1001.rac

; IN NAPTR order pref. flag service regexp replacement

IN NAPTR 200 999 "a" "x-3gpp-sgsn:x-s4" "" topoff.eth1.nri-sgsn02.rac0003.lac1001.rac

IN NAPTR 200 999 "a" "x-3gpp-sgsn:x-s3" "" topoff.eth2.nri-sgsn02.rac0003.lac1001.rac

IN NAPTR 300 999 "a" "x-3gpp-sgsn:x-gn" "" topoff.eth3.nri-sgsn02.rac0003.lac1001.rac

;

; All SGSN IP addresses for both SGSNs

;

topoff.eth1.nri-sgsn01.rac0003.lac1001.rac IN A 192.0.2.11

IN A 192.0.2.12

IN AAAA 2001:db8:0:0:0:0:0:0

IN AAAA 2001:db8:0:1:0:0:0:0

topoff.eth2.nri-sgsn01.rac0003.lac1001.rac IN A 192.0.2.13

IN A 192.0.2.14

IN AAAA 2001:db8:0:2:0:0:0:0

IN AAAA 2001:db8:0:3:0:0:0:0

topoff.eth3.nri-sgsn01.rac0003.lac1001.rac IN A 192.0.2.15

IN A 192.0.2.16

IN AAAA 2001:db8:0:4:0:0:0:0

IN AAAA 2001:db8:0:5:0:0:0:0

topoff.eth1.nri-sgsn02.rac0003.lac1001.rac IN A 192.0.2.17

IN A 192.0.2.18

IN AAAA 2001:db8:0:6:0:0:0:0

IN AAAA 2001:db8:0:7:0:0:0:0

topoff.eth2.nri-sgsn02.rac0003.lac1001.rac IN A 192.0.2.19

IN A 192.0.2.20

IN AAAA 2001:db8:0:8:0:0:0:0

IN AAAA 2001:db8:0:9:0:0:0:0

topoff.eth3.nri-sgsn02.rac0003.lac1001.rac IN A 192.0.2.21

IN A 192.0.2.22

IN AAAA 2001:db8:0:10:0:0:0:0

IN AAAA 2001:db8:0:11:0:0:0:0

; end of file

The partially qualified SGSN host names are topoff.eth1.nri-sgsn01.rac0003.lac1001.rac and topoff.eth1.nri-sgsn02.rac0003.lac1001.rac, and similar.

The fully qualified SGSN node names are the relatively long

nri-sgsn01.rac0003.lac1001.rac.epc.mnc990.mcc311.3gppnetwork.org.

and

nri-sgsn02.rac0003.lac1001.rac.epc.mnc990.mcc311.3gppnetwork.org.

which are obtained by appending the value of $ORIGIN to the partially qualified SGSN node names. As stated before we will use the partially qualified names in this Annex to avoid this visual clutter and for typographical reasons.

D.4 Null-NRI/SGSN Group ID file for DCN

A NAPTR record is required to be provisioned under the RAI FQDN (see clause 5.8.3). The format of the RAI FQDN is rac<RAC>.lac<LAC>.rac as defined in clause 19.4.2.5 of 3GPP TS 23.003 [4].

For this example we have two SGSN pools represented by SGSN Group ID (sgsngi=0001) and Null-NRI (null-nri=0005). Each pool has two SGSNs with NRI code of 1, 2 and 3, 4 respectively.

;

rac0003.lac1001.rac

; IN NAPTR order pref. flag service regexp replacement

IN NAPTR 100 999 "a" "x-3gpp-sgsn:x-gn+ue-1.10.20" "" topoff.eth1.nri-sgsn0001.sgsngi0001.rac0003.lac1001.rac

IN NAPTR 200 999 "a" "x-3gpp-sgsn:x-s16+ue-1.10.20" "" topoff.eth3.nri-sgsn0002.sgsngi0001.rac0003.lac1001.rac

IN NAPTR 100 999 "a" "x-3gpp-sgsn:x-gn+ue-2.5" "" topoff.eth1.nri-sgsn0003.null-nri0005.rac0003.lac1001.rac

IN NAPTR 200 999 "a" "x-3gpp-sgsn:x-s16+ue-2.5" "" topoff.eth3.nri-sgsn0004.null-nri0005.rac0003.lac1001.rac

;

;From above records, Null-NRI and SGSN Group ID information can be retrieved when necessary.

Annex E (Informative):
SGW/PGW selection examples using GTP-C load control

E.1 PGW selection using GTP-C load control at node level

This example illustrates the principles of the SGW or PGW selection specified in clause 4A.2, with GTP-C load control supported and enabled at node level.

The example assumes that the procedures specified in this document have 3 candidate PGWs with the same relative order, (e.g. with the same topological order) and assume that the following weights are received from the DNS and "Load Metric" reported via GTP-C signalling:

PGW1: DNS-weight-factor = 20, Load-metric = 10%

PGW2: DNS-weight-factor = 20, Load-metric = 20%

PGW3: DNS-weight-factor = 60, Load-metric= 30%

Based on the above, the selecting node calculates the effective available load for each candidate PGW:

PGW1-effective-available-load = (100 – 10)% X 20 = 18

PGW2-effective-available-load = (100 – 20)% X 20 = 16

PGW3-effective-available-load = (100 – 30)% X 60 = 42

The selecting node then calculates the relative available load of each candidate PGW (rounding-off to nearest integer value):

PGW1-relative-available-load = 18 / (18 + 16 + 42) =~ 24%

PGW2-relative-available-load = 16 / (18 + 16 + 42) =~ 21%

PGW3-relative-available-load = 42 / (18 + 16 + 42) =~ 55%

Out of the total new session requests, the node selects the PGW1, PGW2 and PGW3 for 24%, 21% and 55% respectively, e.g. per 100 new sessions requests, the PGW1 is selected for 24 sessions, PGW2 for 21 sessions and PGW3 for the remaining 55 new sessions.

E.2 PGW selection using GTP-C load control at APN level

E. 2.1 PGW selection when APN load control information is available for each candidate PGW

This example illustrates the principles of the PGW selection specified in clause 4A.3, with GTP-C load control supported and enabled at node level and APN level.

The example assumes that the procedures specified in this document have 3 candidate PGWs with the same relative order, (e.g. with the same topological order) and assume that the following weights are received from the DNS and APN load control information reported via GTP-C signalling:

PGW1: DNS-weight-factor = 20, APN1-Load-metric = 60%, APN1-relative-capacity = 50%

PGW2: DNS-weight-factor = 20, APN1-Load-metric = 50%, APN1-relative-capacity = 20%

PGW3: DNS-weight-factor = 60, APN1-Load-metric= 50%, APN1-relative-capacity = 10%

Based on the above, the APN1-effective-available-load is calculated as follows:

PGW1-APN1-effective-available-load = (100 – 60)% X 50% X 20 = 4

PGW2-APN1-effective-available-load = (100 – 50)% X 20% X 20 = 2

PGW3-APN1-effective-available-load = (100 – 50)% X 10% X 60 = 3

Then the APN1-relative-available-load is calculated as below (by rounding-off to nearest integer value):

PGW1-APN1-relative-available-load = 4 / (4 + 2 + 3) =~ 45%

PGW2-APN1-relative-available-load = 2 / (4 + 2 + 3) =~ 22%

PGW3-APN1-relative-available-load = 3 / (4 + 2 + 3) =~ 33%

Out of the total new session requests for APN1, the PGW1 is selected for 45%, PGW2 for 22% and PGW3 for 33%, e.g. per 100 new sessions requests for APN1, the PGW1 is selected for 45 sessions, PGW2 for 22 sessions and PGW3 for 33 sessions.

E.2.2 PGW selection when APN load control information is not available for each candidate PGW

This example illustrates the principles of the PGW selection specified in clause 4A.3, with GTP-C load control supported and enabled at node level and APN level.

The example assumes that the procedures specified in this document have 3 candidate PGWs with the same relative order, (e.g. with the same topological order) and assume that the following weights are received from the DNS and APN load control information reported via GTP-C signalling; it is assumed in particular that PGW3 did only report APN load control information for the APN2.

PGW1: DNS-weight-factor = 20, APN1-Load-metric = 60%, APN1-relative-capacity = 50%

PGW2: DNS-weight-factor = 20, APN1-Load-metric = 50%, APN1-relative-capacity = 20%

PGW3: DNS-weight-factor = 60, APN2-Load-metric= 50%, APN2-relative-capacity = 30%, PGW3-Load-Metric 40%

Based on the above, the APN1-effective-available-load for the PGW3 is calculated assuming the following:

PGW3-APN1-relative-capacity = 100% – 30% = 70%

PGW3-APN1-load-metric = {40% – (50% X 30%)} / {(100% – 30%)} = {40% – 15%} / {70%} = ~36%

Annex F (Informative):
Examples for AMF Discovery by 5G AN

F.1 Introduction

This annex provides examples of DNS provisioning for AMF Discovery by 5G AN.

F.2 Preconditions

See annex A.2.

F.3 Example of an AMF Region with 2 AMF Sets

F.3.1 Master file

The master file for this example has following content.

$ORIGIN 5gc.mnc990.mcc311.3gppnetwork.org.

;

$TTL 600 ; 10 minutes – this directive is defined in IETF RFC 2308 not IETF RFC 1035

;

$INCLUDE SOA_DB.txt

;

$INCLUDE AMFSET_DB.txt

;

; End of file

F.3.2 SOA and NS records

See Annex A.3.3.

F.3.3 AMF Set file

The file containing the AMF Set records for this example will be AMFSET_DB.txt and has following NAPTR record content.

In this example, we have two AMF Sets 1 and 2, in AMF Region 48 (hexadecimal), with 2 AMFs available in each AMF Set.

; AMF Set 1 of AMF Region 48

set001.region48.amfset

; IN NAPTR order pref. flag service regexp replacement

IN NAPTR 100 999 "a" "x-3gpp-amf:x-n2" "" topoff.amf11.amf

IN NAPTR 100 999 "a" "x-3gpp-amf:x-n2" "" topoff.amf12.amf

; AMF Set 2 of AMF Region 48

set002.region48.amfset

; IN NAPTR order pref. flag service regexp replacement

IN NAPTR 100 999 "a" "x-3gpp-amf:x-n2" "" topoff.amf21.amf

IN NAPTR 100 999 "a" "x-3gpp-amf:x-n2" "" topoff.amf22.amf

; AMFs IP addresses

;

topoff.amf11.amf IN A 192.0.2.11

IN A 192.0.2.12

IN AAAA 2001:db8:0:0:0:0:0:0

IN AAAA 2001:db8:0:1:0:0:0:0

topoff.amf12.amf IN A 192.0.2.13

IN A 192.0.2.14

IN AAAA 2001:db8:0:2:0:0:0:0

IN AAAA 2001:db8:0:3:0:0:0:0

topoff.amf21.amf IN A 192.0.2.17

IN A 192.0.2.18

IN AAAA 2001:db8:0:6:0:0:0:0

IN AAAA 2001:db8:0:7:0:0:0:0

topoff.amf22.amf IN A 192.0.2.19

IN A 192.0.2.110

IN AAAA 2001:db8:0:8:0:0:0:0

IN AAAA 2001:db8:0:9:0:0:0:0

; end of file

Annex G (Informative):
Examples for selecting an alternative PGW-C/SMF in a PGW-C/SMF Set

G.1 Introduction

This annex provides examples of DNS provisioning for selecting an alternative PGW-C/SMF in a PGW-C/SMF Set by an MME (see clause 5.1.4).

G.2 Preconditions

See annex A.2.

G.3 Example of an PGW-C/SMF Set

G.3.1 Master file

The master file in A.3.2 is appended with the following content.

$ORIGIN epc.mnc990.mcc311.3gppnetwork.org.

;

; $TTL 600 ; 10 minutes – this directive is defined in IETF RFC 2308 not IETF RFC 1035

;

; $INCLUDE SOA_DB.txt

;

$INCLUDE PGWSET_DB.txt

;

; End of file

G.3.2 SOA and NS records

See Annex A.3.3.

G.3.3 PGW-C/SMF Set file

The file containing the PGW-C/SMF Set records for this example will be PGWSET_DB.txt and has following NAPTR record content.

; PGW Set 12

set12.pgwset

; IN NAPTR order pref. flag service regexp replacement

IN NAPTR 100 999 "a" "x-3gpp-pgw:x-s5-gtp:x-s8-gtp" "" topoff.vip1.gw01.nodes

IN NAPTR 200 999 "a" "x-3gpp-pgw:x-s5-gtp:x-s8-gtp" "" topoff.vip1.gw21.nodes

; PGWs IP addresses

;

topoff.vip1.gw01.nodes IN A 192.0.2.11

IN A 192.0.2.12

IN AAAA 2001:db8:0:0:0:0:0:0

IN AAAA 2001:db8:0:1:0:0:0:0

topoff.vip1.gw21.nodes IN A 192.0.2.13

IN A 192.0.2.14

IN AAAA 2001:db8:0:2:0:0:0:0

IN AAAA 2001:db8:0:3:0:0:0:0

; end of file

Annex H (Informative):
Change history

Date

TSG #

TSG Doc.

CR

Rev

Cat

Subject/Comment

New

2008-12

CT#42

CP-080714

V2.0.0 approved in CT#42

8.0.0

2009-03

CT#43

CP-090054

0001

1

DNS examples

8.1.0

0002

2

DNS  cleanup regarding topon/topoff

0003

1

Missing clause for node name records of SGW

0004

1

DNS Editorial cleanup

0005

SGW Selection for TAU and Handover

0007

1

Correction to DNS procedures

0008

2

Clarifications to NAPTR flag usage

0009

1

2009-06

CT#44

CP-090291

0010

1

Home agent discovery

8.2.0

0011

1

Correction for PGW selection for colocated PGW/GGSN

0012

1

Handling when hostnames are missing topon/topoff

0013

1

Release 8 SGSN clarifications

2009-06

CT#44

CP-090542

0015

Incorrect FQDN nodes.mnc<MNC>.mcc<MCC>.3gppnetwork.org

8.3.0

0017

3

Failure of DNS procedures

0018

1

Correction about discovering and selecting a PGW and SGW

2009-12

Update to Rel-9 version (MCC)

9.0.0

2010-03

CT#47

CP-100019

0024

2

APN-FQDN construction

9.1.0

2010-09

CT#49

CP-100457

0027

1

Construction of APN-FQDN

9.2.0

2010-12

CT#50

CP-100678

0030

3

Add missing MME/SGSN selection for the RIM procedure

9.3.0

2010-12

CT#50

CP-100686

0029

1

PGW selection by ePDG with GTP over S2b

10.0.0

CP-100684

0033

3

SIPTO support in DNS

CP-100684

0036

2

GW selection for SIPTO based on eNodeB id

CP-100693

0034

Correcting clause numbers in Annex A.3

CP-100693

0035

1

Clarifications to DNS Based GW Selection in Roaming Cases

CP-100693

0037

1

Correction in Annex C

2011-03

CT#51

CP-110057

0038

2

GGSN selection for SIPTO APN

10.1.0

CP-110057

0045

2

GW selection based on RAI/RNC-ID/TAI/eNodeb ID

CP-110056

0039

2

PGW selection for LIPA

CP-110076

0042

1

Adding SGSN selection cases

CP-110076

0044

2

DNS Service for Sv

CP-110076

0047

1

MME selection

CP-110088

0043

3

DNS procedure for Relay Node OAM system discovery

CP-110059

0046

Service parameter for the GTP based S2b

2011-06

CT#52

CP-110364

0051

1

Services of a MME from MME node name

10.2.0

CP-110374

0049

1

SGSN Selection

2011-07

Editorial correction to history table.

10.2.1

2011-09

CT#53

CP-110567

0056

2

SGSN selection

10.3.0

2012-03

CT#55

CP-120028

0058

1

SGSN selection

11.0.0

CP-120045

0061

1

PGW discovery for GTP based S2a

2012-06

CT#56

CP-120234

0062

2

DNS procedure for CS to PS SRVCC

11.1.0

2012-09

CT#57

CP-120447

0064

1

PGW selection in eHRPD for SIPTO

11.2.0

CP-120457

0065

1

SGW selection based on eNodeB ID

2013-06

CT#60

CP-130378

0067

1

GWs selection for SIPTO at the local network

12.0.0

2013-09

CT#61

CP-130453

0069

2

SGW selection for SIPTO at the Local Network

12.1.0

CP-130462

0070

2

GERAN Iu Mode

2013-12

CT#62

CP-130620

0071

1

SGW selection for SIPTO at the Local Home Network

12.2.0

2014-06

CT#64

CP-140230

0076

1

Cleanup the pre-Release-8 DNS procedure on Release-8 SGSN

12.3.0

2014-09

CT#65

CP-140505

0077

2

SGW/PGW selection with GTP-C node level load control

12.4.0

CP-140505

0078

2

PGW selection with GTP-C APN level Load Control

2014-12

CT#66

CP-140797

0079

3

MME and SGSN selection by RCAF

13.0.0

2015-06

CT#68

CP-150270

0080

3

Multiple IP addresses in DNS Record

13.1.0

2015-12

CT#70

CP-150781

0082

2

DNS procedures for Decor

13.2.0

CP-150765

0083

Priority ordering of SRV records

2016-03

CT#71

CP-160038

0084

1

GTP-C Load Control – Mix of NAPTR records with "s" and "a" flags

13.3.0

CP-160022

0085

1

Clarification on the use of UE Usage Type

CP-160022

0086

4

DNS procedures for Decor

CP-160033

0087

3

Impacts on the DNS procedures for CIoT with introduction of NB-IoT and Non-IP

2016-06

CT#72

CP-160224

0088

1

MME and SGSN selection procedures for Dedicated Core Networks

13.4.0

2016-06

CT#72

CP-160228

0089

2

Clarification on the DNS impact for CIoT

13.4.0

2016-09

CT#73

CP-160435

0090

1

Use of DNS to select a GGSN handling Non-IP data

14.0.0

2016-12

CT#74

CP-160680

0092

1

Use of DéCOR for NonIP_GPRS

14.1.0

2016-12

CT#74

CP-160680

0096

GW selection by S4-SGSN for Non-IP PDN type

14.1.0

2016-12

CT#74

CP-160665

0094

1

DECOR for GPRS Core

14.1.0

2017-06

CT#76

CP-171036

0097

1

UP function selection by DNS

14.2.0

2017-09

CT#77

CP-172015

0099

PGW selection for WLAN with deployed DCNs

14.3.0

2017-09

CT#77

CP-172020

0100

Missing CUPS stage 3 reference

14.3.0

2017-12

CT#78

CP-173036

0104

4

SGW/PGW selection for NR

15.0.0

2018-03

CT#79

CP-180020

0107

1

Correction for indicating DCNR to Combined SGW/PGW

15.1.0

2018-06

CT#80

CP-181132

0108

1

Selection of a combined PGW/SMF for interworking with 5GS

15.2.0

2018-09

CT#81

CP-182067

0109

DNS records for selecting a node with a network capability in a Dedidated Core Network

15.3.0

2018-09

CT#81

CP-182084

0110

1

EPS interworking with 5GS

15.3.0

2018-09

CT#81

CP-182084

0111

1

AMF Discovery by 5G AN

15.3.0

2018-12

CT#82

CP-183092

0115

3

Procedures to support interworking with 5GC

15.4.0

2018-12

CT#82

CP-183092

0116

Corrections to references in clause 7.2

15.4.0

2018-12

CT#82

CP-183092

0117

1

EPS interworking with 5GS

15.4.0

2019-03

CT#83

CP-190032

0118

PGW/SMF selection by ePDG

15.5.0

2019-03

CT#83

CP-190032

0119

Incomplete references for AMF discovery and selection by MME

15.5.0

2019-09

CT#85

CP-192188

0120

1

Selection of MME_SRVCC

16.0.0

2019-09

CT#85

CP-192126

0121

1

DNS procedures to support Ethernet PDN

16.0.0

2019-12

CT#86

CP-193041

0122

1

UEs not supporting 5GC NAS with a 5GS subscription

16.1.0

2020-03

CT87e

CP-200021

0126

UCMF Selection by MMEs

16.2.0

2020-06

CT#88e

CP-201062

0127

Service parameter for SGW

16.3.0

2020-12

CT#90e

CP-203058

0129

1

Support of PGW-C/SMF change

17.0.0

2021-03

CT#91e

CP-210049

0131

DCN support for AMF discovery

17.1.0

2021-12

CT#94e

CP-213097

0132

B

Procedure to select a combined UPF/MB-UPF

17.2.0

2022-03

CT#95e

CP-220092

0133

1

F

Incorrect reference in clause 7.2

17.3.0