diff options
| author | Pau Espin Pedrol <pespin@sysmocom.de> | 2019-04-16 15:47:59 +0200 |
|---|---|---|
| committer | Pau Espin Pedrol <pespin@sysmocom.de> | 2019-05-13 17:54:44 +0200 |
| commit | 18506c850c3bbcbfa814e07dc02a17fdb5f7bb9a (patch) | |
| tree | dc184100572bce10bf914f030f35f18387d8db7c /src/gsm | |
| parent | 38176d297d63af994dcd2d96bdc0b93895db98dd (diff) | |
gsm0808: Introduce Osmocom extensions to announce Osmux support
IE GSM0808_IE_OSMO_OSMUX_SUPPORT (T, 1 byte) is sent in AoIP appended to
BSSMAP RESET in order to announce the peer that its MGW supports handling
Osmux streams upon call set up.
IE GSM0808_IE_OSMO_OSMUX_CID (TV, T 1 byte & V 1 byte) is sent in AoIP
during call set up:
* MSC->BSC Assignment Request
* BSC->MSC Assignemnt Complete
The 1 byte value contains the local Osmux CID, aka the recvCID aka CID where the
peer sending the Assign Req/Compl will look for Osmux frames on that
call. Hence, the peer receiving this CID value must use it to send Osmux
frames for that call.
As a result, a given call leg BSC<->MSC can have one different Osmux CID
per direction. For example:
* MS => MGW_BSC ==CID 0==> MGW_MSC
* MS <= MGW_BSC <=CID 1=== MGW_MSC
This allows for setups with 256 call legs per BSC on scenarios where NAT
is not a problem, where MSC can have a pool of 256 CID per MGW_BSC (or
remote peer).
Related: OS#2551
Change-Id: I28f83e2e32b9533c99e65ccc1562900ac2aec74e
Diffstat (limited to 'src/gsm')
| -rw-r--r-- | src/gsm/gsm0808.c | 4 | ||||
| -rw-r--r-- | src/gsm/gsm0808_utils.c | 19 | ||||
| -rw-r--r-- | src/gsm/libosmogsm.map | 1 |
3 files changed, 24 insertions, 0 deletions
diff --git a/src/gsm/gsm0808.c b/src/gsm/gsm0808.c index 3c77c77a..514d7f22 100644 --- a/src/gsm/gsm0808.c +++ b/src/gsm/gsm0808.c @@ -1387,6 +1387,10 @@ static const struct tlv_definition bss_att_tlvdef = { [GSM0808_IE_CN_TO_MS_TRANSP_INFO] = { TLV_TYPE_TLV }, [GSM0808_IE_SELECTED_PLMN_ID] = { TLV_TYPE_FIXED, 3 }, [GSM0808_IE_LAST_USED_EUTRAN_PLMN_ID] = { TLV_TYPE_FIXED, 3 }, + + /* Osmocom extensions */ + [GSM0808_IE_OSMO_OSMUX_SUPPORT] = { TLV_TYPE_T }, + [GSM0808_IE_OSMO_OSMUX_CID] = { TLV_TYPE_TV }, }, }; diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c index e8259300..26f7944d 100644 --- a/src/gsm/gsm0808_utils.c +++ b/src/gsm/gsm0808_utils.c @@ -172,6 +172,25 @@ int gsm0808_dec_aoip_trasp_addr(struct sockaddr_storage *ss, return (int)(elem - old_elem); } +/*! Decode TS 08.08 (Osmocom Extension) Osmux CID + * TV with len(V) == 1, and V is the CID to be used. + * \param[out] cid Caller-provided variable where CID is stored + * \param[in] elem pointer to IE value + * \param[in] len length of \a elem in bytes + * \returns number of bytes parsed */ +int gsm0808_dec_osmux_cid(uint8_t *cid, const uint8_t *elem, uint8_t len) +{ + OSMO_ASSERT(cid); + if (!elem) + return -EINVAL; + if (len != 1) + return -EINVAL; + + *cid = *elem; + + return 1; +} + #endif /* HAVE_SYS_SOCKET_H */ /* Helper function for gsm0808_enc_speech_codec() diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index 840bac9c..0f4a0db1 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -198,6 +198,7 @@ gsm0808_prepend_dtap_header; gsm0808_enc_cause; gsm0808_enc_aoip_trasp_addr; gsm0808_dec_aoip_trasp_addr; +gsm0808_dec_osmux_cid; gsm0808_enc_speech_codec; gsm0808_dec_speech_codec; gsm0808_enc_speech_codec_list; |