From 18506c850c3bbcbfa814e07dc02a17fdb5f7bb9a Mon Sep 17 00:00:00 2001 From: Pau Espin Pedrol Date: Tue, 16 Apr 2019 15:47:59 +0200 Subject: 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 --- src/gsm/gsm0808.c | 4 ++++ src/gsm/gsm0808_utils.c | 19 +++++++++++++++++++ src/gsm/libosmogsm.map | 1 + 3 files changed, 24 insertions(+) (limited to 'src') 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; -- cgit v1.2.3